swift--枚举
2015-09-22 21:50
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出自http://blog.csdn.net/woaifen3344/article/details/29611659
Swift中的枚举与C、OC中的枚举有很大的区别，增加了原来类中都有的特性到枚举中。
定义枚举的语法：
[objc] view
plaincopyprint?
enum SimeEnum {
// enumeration goes here
}
定义一个指南针的四个方向的枚举：
[objc] view
plaincopyprint?
// 使用case来表示新成员的定义开始
enum CompassPoint {
case North
case South
case East
case West
}
// 使用枚举
[objc] view
plaincopyprint?
var direction = CompassPoint.West
// 再次修改时，可以不指定枚举，而可以只使用.引用
[objc] view
plaincopyprint?
direction = .North
下面是引用 BY 史薇芙特 ·
2014年6月5日
枚举定义了一个常用的具有相关性的一组数据，并在你的代码中以一个安全的方式使用它们。
如果你熟悉C语言，你就会知道，C语言中的枚举指定相关名称为一组整数值。在Swift中枚举更为灵活，不必为枚举的每个成员提供一个值。如果一个值（被称为“原始”的值）被提供给每个枚举成员，则该值可以是一个字符串，一个字符，或者任何整数或浮点类型的值。
另外，枚举成员可以指定任何类型，每个成员都可以存储的不同的相关值，就像其他语言中使用集合或变体。你还可以定义一组通用的相关成员为一个枚举，每一种都有不同的一组与它相关的适当类型的值的一部分。
在Swift中枚举类型是最重要的类型。它采用了很多以前只有类才具有的特性，如计算性能，以提供有关枚举的当前值的更多信息，方法和实例方法提供的功能相关的枚举表示的值传统上支持的许多功能。枚举也可以定义初始化，以提供一个初始成员值;可以在原有基础上扩展扩大它们的功能;并使用协议来提供标准功能。
欲了解更多有关这些功能，请参见Properties, Methods, Initialization, Extensions, Protocols
1、枚举语法
使用枚举enum关键词并把他们的整个定义在一对大括号内：
下面是一个指南针的四个点一个例子：
在枚举中定义的值（如North，South，East和West）是枚举的成员值（或成员）。这个例子里case关键字表示成员值一条新的分支将被定义。
Note
不像C和Objective-C，Swift枚举成员在创建时不分配默认整数值。在上面的例子CompassPoints中North，South，Eath，West不等于隐含0，1，2和3，而是一种与CompassPoint明确被定义的类型却各不相同的值。
多个成员的值可以出现在一行上，用逗号分隔：
每个枚举定义中定义了一个全新的类型。像其他Swift的类型，它们的名称（如CompassPoint和Planet）应为大写字母。给枚举类型单数而不是复数的名字，这样理解起来更加容易如：
使用directionToHead的类型时，用CompassPoint的一个可能值初始化的推断。一旦directionToHead被声明为一个CompassPoint，您可以将其设置为使用更短的.语法而不用再书写枚举CompassPoint值本身：
directionToHead的类型是已知的，所以你可以在设定它的值时，不写该类型。使用类型明确的枚举值可以让代码具有更好的可读性。
2、匹配枚举值与switch语句
你可以使用单个枚举值匹配switch语句：
你可以理解这段代码：
“考虑directionToHead的价值。当它等于North，打印“Lots of planets have a north”。当它等于South，打印“Watch out for penguins”等等。
正如控制流所描述，Switch语句考虑枚举的成员,如果省略了West时，这段代码无法编译，因为它没有考虑CompassPoint成员的完整性。Switch语句要求全面性确保枚举成员，避免不小心漏掉情况发生。
当它不需要为每一个枚举成员都匹配的情况下，你可以提供一个默认default分支来涵盖未明确提到的任何成员：
3、关联值
在上一节中的示例延时了一个枚举的成员是如何被定义（分类）的。你可以为Planet.Earth设置一个常量或变量，然后在代码中检查这个值。但是，它有时是有用的才能存储其它类型的关联值除了这些成员的值。这让你随着成员值存储额外的自定义信息，并允许在你的代码中来使用该信息。
Swift的枚举类型可以由一些数据类型相关的组成，如果需要的话，这些数据类型可以是各不相同的。枚举的这种特性跟其它语言中的奇异集合，标签集合或者变体相似
例如，假设一个库存跟踪系统需要由两种不同类型的条形码来跟踪产品。有些产品上标有UPC-A代码格式，它使用数字0到9的一维条码，每一个条码都有一个“数字系统”的数字，后跟十“标识符”的数字。最后一位是“检查”位，以验证代码已被正确扫描：
其他产品都贴有二维条码QR码格式，它可以使用任何的ISO8859-1字符，并可以编码字符串，最多2,953个字符：
这将是方便的库存跟踪系统能够存储UPC-A条码作为三个整数的元组，和QR代码的条形码的任何长度的字符串。
在Swift中可以使用一个枚举来定义两种类型的产品条形码，结构可以是这样的：
这可以被理解为：
“定义一个名为条形码枚举类型，它可以是UPC-A的任一值类型的关联值（Int，Int，Int），或QRCode的一个类型为String的关联值。”
这个定义不提供任何实际的Int或String值，它只是定义了条形码常量和变量当等于Barcode.UPCA或Barcode.QRCode关联值的类型的时候的存储形式。
然后可以使用任何一种类型来创建新的条码：
此示例创建一个名为productBarcode新的变量，并与相关联的元组值赋给它Barcode.UPCA的值（8，8590951226，3）。提供的“标识符”值都有整数加下划线的文字，85909_51226，使其更易于阅读的条形码。
同一产品可以分配不同类型的条形码：
在这一点上，原来Barcode.UPCA和其整数值被新的Barcode.QRCode及其字符串值代替。_条形码的常量和变量可以存储任何一个_UPCA或QRCode的（连同其关联值），但它们只能存储其中之一在任何指定时间。
不同的条码类型像以前一样可以使用一个switch语句来检查，但是这一次相关的值可以被提取作为switch语句的一部分。您提取每个相关值作为常数（let前缀）或变量（var前缀）不同的情况下，在switch语句的case代码内使用：
如果所有的枚举成员的关联值的提取为常数，或者当所有被提取为变量，为了简洁起见，可以放置一个var，或let标注在成员名称前：
4、原始值
在关联值的条形码的例子演示了一个枚举的成员如何能声明它们存储不同类型的关联值。作为替代关联值，枚举成员可以拿出预先填入缺省值（称为原始值），从而具有相同的类型。
这里是一个存储原始的ASCII值命名枚举成员的一个例子：
在这里，原始值被定义为字符类型的枚举叫做ASCIIControlCharacter，并设置了一些比较常见的ASCII控制字符。字符值的字符串和字符的描述。
注意，原始值是不相同关联值。原始值设置为预填充的值时，应先在你的代码中定义枚举，像上述三个ASCII码。对于一个特定的枚举成员的原始值始终是相同的。当你创建一个基于枚举的常量或变量的新成员的关联值设置，每次当你这样做的时候可以是不同的。
原始值可以是字符串，字符，或任何整数或浮点数类型。每个原始值必须在它的枚举中唯一声明。当整数被用于原始值，如果其他枚举成员没有值时，它们自动递增。
下面列举的是一个细化的早期Planet枚举，使用原始整数值来表示每个Planet的太阳系的顺序：
自动递增意味着Planet.Venus具有2的原始值，依此类推。
访问其toRaw方法枚举成员的原始值：
使用枚举的fromRaw方法来试图找到一个特定的原始值枚举成员。这个例子识别Uranus的位置通过原始值为7：
然而，并非所有可能的Int值都会找到一个匹配的星球。正因如此，该fromRaw方法返回一个可选的枚举成员。在上面的例子中，是possiblePlanet类型Planet？或“可选的Planet”。
如果你试图找到一个Planet为9的位置，通过fromRaw返回可选的Planet值将是无：
这个范例使用somePlanet= Planet.fromRaw(9)来尝试访问可选集合Planet，在可选Planet集合中设置检索条件somePlanet，在原始值为9的情况下，不能检索到位置为9的星球，所有else分支被执行。
Swift中的枚举与C、OC中的枚举有很大的区别，增加了原来类中都有的特性到枚举中。
定义枚举的语法：
[objc] view
plaincopyprint?
enum SimeEnum {
// enumeration goes here
}
定义一个指南针的四个方向的枚举：
[objc] view
plaincopyprint?
// 使用case来表示新成员的定义开始
enum CompassPoint {
case North
case South
case East
case West
}
// 使用枚举
[objc] view
plaincopyprint?
var direction = CompassPoint.West
// 再次修改时，可以不指定枚举，而可以只使用.引用
[objc] view
plaincopyprint?
direction = .North
下面是引用 BY 史薇芙特 ·
2014年6月5日
枚举定义了一个常用的具有相关性的一组数据，并在你的代码中以一个安全的方式使用它们。
如果你熟悉C语言，你就会知道，C语言中的枚举指定相关名称为一组整数值。在Swift中枚举更为灵活，不必为枚举的每个成员提供一个值。如果一个值（被称为“原始”的值）被提供给每个枚举成员，则该值可以是一个字符串，一个字符，或者任何整数或浮点类型的值。
另外，枚举成员可以指定任何类型，每个成员都可以存储的不同的相关值，就像其他语言中使用集合或变体。你还可以定义一组通用的相关成员为一个枚举，每一种都有不同的一组与它相关的适当类型的值的一部分。
在Swift中枚举类型是最重要的类型。它采用了很多以前只有类才具有的特性，如计算性能，以提供有关枚举的当前值的更多信息，方法和实例方法提供的功能相关的枚举表示的值传统上支持的许多功能。枚举也可以定义初始化，以提供一个初始成员值;可以在原有基础上扩展扩大它们的功能;并使用协议来提供标准功能。
欲了解更多有关这些功能，请参见Properties, Methods, Initialization, Extensions, Protocols
1、枚举语法
使用枚举enum关键词并把他们的整个定义在一对大括号内：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span> | <span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">enum</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">SomeEnumeration</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(102, 102, 102);"><em><span class="com" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">// enumeration definition goes here</span></em></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span> |
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> | <span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">enum</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">CompassPoint</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">North</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">South</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">East</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">West</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span> |
Note
不像C和Objective-C，Swift枚举成员在创建时不分配默认整数值。在上面的例子CompassPoints中North，South，Eath，West不等于隐含0，1，2和3，而是一种与CompassPoint明确被定义的类型却各不相同的值。
多个成员的值可以出现在一行上，用逗号分隔：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span> | <span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">enum</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Planet</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Mercury</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Venus</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Earth</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Mars</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Jupiter</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Saturn</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Uranus</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Neptune</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span> |
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span> | <span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline;"><strong><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">var</span></strong></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> directionToHead </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">CompassPoint</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">West</span> |
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span> | <span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">directionToHead </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">East</span> |
2、匹配枚举值与switch语句
你可以使用单个枚举值匹配switch语句：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> | <span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">directionToHead </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">South</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">switch</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> directionToHead </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">North</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"Lots of planets have a north"</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">South</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"Watch out for penguins"</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">East</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"Where the sun rises"</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">West</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"Where the skies are blue"</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(102, 102, 102);"><em><span class="com" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">// prints "Watch out for penguins"</span></em></span> |
“考虑directionToHead的价值。当它等于North，打印“Lots of planets have a north”。当它等于South，打印“Watch out for penguins”等等。
正如控制流所描述，Switch语句考虑枚举的成员,如果省略了West时，这段代码无法编译，因为它没有考虑CompassPoint成员的完整性。Switch语句要求全面性确保枚举成员，避免不小心漏掉情况发生。
当它不需要为每一个枚举成员都匹配的情况下，你可以提供一个默认default分支来涵盖未明确提到的任何成员：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> | <span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">let somePlanet </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Planet</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Earth</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">switch</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> somePlanet </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Earth</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"Mostly harmless"</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">default</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"Not a safe place for humans"</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(102, 102, 102);"><em><span class="com" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">// prints "Mostly harmless"</span></em></span> |
在上一节中的示例延时了一个枚举的成员是如何被定义（分类）的。你可以为Planet.Earth设置一个常量或变量，然后在代码中检查这个值。但是，它有时是有用的才能存储其它类型的关联值除了这些成员的值。这让你随着成员值存储额外的自定义信息，并允许在你的代码中来使用该信息。
Swift的枚举类型可以由一些数据类型相关的组成，如果需要的话，这些数据类型可以是各不相同的。枚举的这种特性跟其它语言中的奇异集合，标签集合或者变体相似
例如，假设一个库存跟踪系统需要由两种不同类型的条形码来跟踪产品。有些产品上标有UPC-A代码格式，它使用数字0到9的一维条码，每一个条码都有一个“数字系统”的数字，后跟十“标识符”的数字。最后一位是“检查”位，以验证代码已被正确扫描：
其他产品都贴有二维条码QR码格式，它可以使用任何的ISO8859-1字符，并可以编码字符串，最多2,953个字符：
这将是方便的库存跟踪系统能够存储UPC-A条码作为三个整数的元组，和QR代码的条形码的任何长度的字符串。
在Swift中可以使用一个枚举来定义两种类型的产品条形码，结构可以是这样的：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> | <span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">enum</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Barcode</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> UPCA</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Int</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Int</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Int</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">QRCode</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">String</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span> |
“定义一个名为条形码枚举类型，它可以是UPC-A的任一值类型的关联值（Int，Int，Int），或QRCode的一个类型为String的关联值。”
这个定义不提供任何实际的Int或String值，它只是定义了条形码常量和变量当等于Barcode.UPCA或Barcode.QRCode关联值的类型的时候的存储形式。
然后可以使用任何一种类型来创建新的条码：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span> | <span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline;"><strong><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">var</span></strong></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> productBarcode </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Barcode</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">UPCA</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(204, 102, 204);"><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">8</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(204, 102, 204);"><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">85909</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">_51226</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(204, 102, 204);"><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span> |
同一产品可以分配不同类型的条形码：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span> | <span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">productBarcode </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">QRCode</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"ABCDEFGHIJKLMNOP"</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span> |
不同的条码类型像以前一样可以使用一个switch语句来检查，但是这一次相关的值可以被提取作为switch语句的一部分。您提取每个相关值作为常数（let前缀）或变量（var前缀）不同的情况下，在switch语句的case代码内使用：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> | <span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">switch</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> productBarcode </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">UPCA</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">let numberSystem</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> let identifier</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> let check</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"UPC-A with value of \(numberSystem), \(identifier), \(check)."</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">QRCode</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">let productCode</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"QR code with value of \(productCode)."</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(102, 102, 102);"><em><span class="com" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">// prints "QR code with value of ABCDEFGHIJKLMNOP."</span></em></span> |
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> | <span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">switch</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> productBarcode </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> let </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">UPCA</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">numberSystem</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> identifier</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> check</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"UPC-A with value of \(numberSystem), \(identifier), \(check)."</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> let </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">QRCode</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">productCode</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"QR code with value of \(productCode)."</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(102, 102, 102);"><em><span class="com" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">// prints "QR code with value of ABCDEFGHIJKLMNOP."</span></em></span> |
在关联值的条形码的例子演示了一个枚举的成员如何能声明它们存储不同类型的关联值。作为替代关联值，枚举成员可以拿出预先填入缺省值（称为原始值），从而具有相同的类型。
这里是一个存储原始的ASCII值命名枚举成员的一个例子：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> | <span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">enum</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">ASCIIControlCharacter</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Character</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Tab</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 153);"><strong><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">\t</span></strong></span><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">LineFeed</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 153);"><strong><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">\n</span></strong></span><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">CarriageReturn</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 153);"><strong><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">\r</span></strong></span><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span> |
注意，原始值是不相同关联值。原始值设置为预填充的值时，应先在你的代码中定义枚举，像上述三个ASCII码。对于一个特定的枚举成员的原始值始终是相同的。当你创建一个基于枚举的常量或变量的新成员的关联值设置，每次当你这样做的时候可以是不同的。
原始值可以是字符串，字符，或任何整数或浮点数类型。每个原始值必须在它的枚举中唯一声明。当整数被用于原始值，如果其他枚举成员没有值时，它们自动递增。
下面列举的是一个细化的早期Planet枚举，使用原始整数值来表示每个Planet的太阳系的顺序：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span> | <span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">enum</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Planet</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Int</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Mercury</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(204, 102, 204);"><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Venus</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Earth</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Mars</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Jupiter</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Saturn</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Uranus</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">,</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Neptune</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span> |
访问其toRaw方法枚举成员的原始值：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span> | <span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">let earthsOrder </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Planet</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Earth</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">toRaw</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(102, 102, 102);"><em><span class="com" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">// earthsOrder is 3</span></em></span> |
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span> | <span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">let possiblePlanet </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Planet</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">fromRaw</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(204, 102, 204);"><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">7</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(102, 102, 102);"><em><span class="com" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">// possiblePlanet is of type Planet? and equals Planet.Uranus</span></em></span> |
如果你试图找到一个Planet为9的位置，通过fromRaw返回可选的Planet值将是无：
<span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">1</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">2</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">3</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> | <span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">let positionToFind </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(204, 102, 204);"><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(25, 95, 145);">9</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">if</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> let somePlanet </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">=</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Planet</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">fromRaw</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">positionToFind</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">switch</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> somePlanet </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">case</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: teal;">Earth</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"Mostly harmless"</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">default</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(51, 153, 51);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"Not a safe place for humans"</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(177, 177, 0);"><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(30, 52, 123);">else</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);"> </span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">{</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
println</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">(</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 0, 255);"><span class="str" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(221, 17, 68);">"There isn't a planet at position \(positionToFind)"</span></span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(0, 153, 0);"><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">}</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(72, 72, 76);">
</span><span style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(102, 102, 102);"><em><span class="com" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant: inherit; line-height: inherit; vertical-align: baseline; color: rgb(147, 161, 161);">// prints "There isn't a planet at position 9"</span></em></span> |
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