Objective C Foundation框架（NSNumber）

1.认识Foundation框架

框架是由许多类、方法、函数以及文档按照一定规则组织起来的集合，以便于程序员更方便、迅速的开发程序。Cocoa程序编写主要用了两个框架Foundation和ApplicationKit（UIKit）。其中Foundation框架主要定义了一些基础类包括有NSNumber、NSString、NSDate等等。UIKit框架主要用于一些用户界面设计的类包括有UIView、UILabel、UIButton等等。其中常用于类中的前缀“NS”就来自于Cocoa的来源“NextSTEP”公司。



2.NSNumber数字对象的常用处理方法

Objective C中采用的是消息机制，所以基本数据类型的变量，是不能够向他们发送消息的。只有是对象，才能够享有发送消息的权利。

继承关系：NSNumber继承自NSValue，NSValue继承自NSObject

NSNumber对象的创建初始化方法：

//类方法创建NSNumber对象
int i = 10;
NSNumber *iNumber = [NSNumber numberWithInt:i];

BOOL b = YES;
NSNumber *bNumber = [NSNumber numberWithBool:b];

//实例法创建NSNumber对象
char c = 'a';
NSNumber *cNumber = [[NSNumber alloc] initWithChar:c];

float fl = YES;
NSNumber *flNumber = [[NSNumber alloc] initWithFloat:fl];

数字对象与基本类型的转换：

//还原成基本类型
i = [iNumber intValue];
b = [bNumber boolValue];
c = [cNumber charValue];
fl = [flNumber floatValue];

Xcode4.5以后的新语法：

//最新语法
NSNumber *nNumber = @123;
NSNumber *floatNumber = @3.13323;
NSNumber *boolNumber = @YES;
NSNumber *charNumber = @'z';
NSNumber *numNumber = @(123+num);

NSNumber中的所有方法：

@property (readonly) char charValue;
@property (readonly) unsigned char unsignedCharValue;
@property (readonly) short shortValue;
@property (readonly) unsigned short unsignedShortValue;
@property (readonly) int intValue;
@property (readonly) unsigned int unsignedIntValue;
@property (readonly) long longValue;
@property (readonly) unsigned long unsignedLongValue;
@property (readonly) long long longLongValue;
@property (readonly) unsigned long long unsignedLongLongValue;
@property (readonly) float floatValue;
@property (readonly) double doubleValue;
@property (readonly) BOOL boolValue;
@property (readonly) NSInteger integerValue NS_AVAILABLE(10_5, 2_0);
@property (readonly) NSUInteger unsignedIntegerValue NS_AVAILABLE(10_5, 2_0);
@property (readonly, copy) NSString *stringValue;

- (NSComparisonResult)compare:(NSNumber *)otherNumber;
- (BOOL)isEqualToNumber:(NSNumber *)number;
- (NSString *)descriptionWithLocale:(id)locale;

- (NSNumber *)initWithChar:(char)value;
- (NSNumber *)initWithUnsignedChar:(unsigned char)value;
- (NSNumber *)initWithShort:(short)value;
- (NSNumber *)initWithUnsignedShort:(unsigned short)value;
- (NSNumber *)initWithInt:(int)value;
- (NSNumber *)initWithUnsignedInt:(unsigned int)value;
- (NSNumber *)initWithLong:(long)value;
- (NSNumber *)initWithUnsignedLong:(unsigned long)value;
- (NSNumber *)initWithLongLong:(long long)value;
- (NSNumber *)initWithUnsignedLongLong:(unsigned long long)value;
- (NSNumber *)initWithFloat:(float)value;
- (NSNumber *)initWithDouble:(double)value;
- (NSNumber *)initWithBool:(BOOL)value;
- (NSNumber *)initWithInteger:(NSInteger)value NS_AVAILABLE(10_5, 2_0);
- (NSNumber *)initWithUnsignedInteger:(NSUInteger)value NS_AVAILABLE(10_5, 2_0);

+ (NSNumber *)numberWithChar:(char)value;
+ (NSNumber *)numberWithUnsignedChar:(unsigned char)value;
+ (NSNumber *)numberWithShort:(short)value;
+ (NSNumber *)numberWithUnsignedShort:(unsigned short)value;
+ (NSNumber *)numberWithInt:(int)value;
+ (NSNumber *)numberWithUnsignedInt:(unsigned int)value;
+ (NSNumber *)numberWithLong:(long)value;
+ (NSNumber *)numberWithUnsignedLong:(unsigned long)value;
+ (NSNumber *)numberWithLongLong:(long long)value;
+ (NSNumber *)numberWithUnsignedLongLong:(unsigned long long)value;
+ (NSNumber *)numberWithFloat:(float)value;
+ (NSNumber *)numberWithDouble:(double)value;
+ (NSNumber *)numberWithBool:(BOOL)value;
+ (NSNumber *)numberWithInteger:(NSInteger)value NS_AVAILABLE(10_5, 2_0);
+ (NSNumber *)numberWithUnsignedInteger:(NSUInteger)value NS_AVAILABLE(10_5, 2_0);