javascript的基础小技巧蛮实用的

1.document.write(""); 输出语句

2.JS中的注释为//

3.传统的HTML文档顺序是:document->html->(head,body)

4.一个浏览器窗口中的DOM顺序是:window->(navigator,screen,history,location,document)

5.得到表单中元素的名称和值:document.getElementById("表单中元素的ID号").name(或value)

6.一个小写转大写的JS: document.getElementById("output").value = document.getElementById("input").value.toUpperCase();

7.JS中的值类型:String,Number,Boolean,Null,Object,Function

8.JS中的字符型转换成数值型:parseInt(),parseFloat()

9.JS中的数字转换成字符型:(""+变量)

10.JS中的取字符串长度是:(length)

11.JS中的字符与字符相连接使用+号.

12.JS中的比较操作符有:==等于,!=不等于,>,>=,<.<=

13.JS中声明变量使用:var来进行声明

14.JS中的判断语句结构:if(condition){}else{}

15.JS中的循环结构:for([initial expression];[condition];[upadte expression]) {inside loop}

16.循环中止的命令是:break

17.JS中的函数定义:function functionName([parameter],...){statement[s]}

18.当文件中出现多个form表单时.可以用document.forms[0],document.forms[1]来代替.

19.窗口:打开窗口window.open(), 关闭一个窗口:window.close(), 窗口本身:self

20.状态栏的设置:window.status="字符";

21.弹出提示信息:window.alert("字符");

22.弹出确认框:window.confirm();

23.弹出输入提示框:window.prompt();

24.指定当前显示链接的位置:window.location.href="URL"

25.取出窗体中的所有表单的数量:document.forms.length

26.关闭文档的输出流:document.close();

27.字符串追加连接符:+=

28.创建一个文档元素:document.createElement(),document.createTextNode()

29.得到元素的方法:document.getElementById()

30.设置表单中所有文本型的成员的值为空:

var form = window.document.forms[0]

for (var i = 0; i<form.elements.length;i++){

if (form.elements.type == "text"){

form.elements.value = "";

}

}

31.复选按钮在JS中判断是否选中:document.forms[0].checkThis.checked (checked属性代表为是否选中返回TRUE或FALSE)

32.单选按钮组(单选按钮的名称必须相同):取单选按钮组的长度document.forms[0].groupName.length

33.单选按钮组判断是否被选中也是用checked.

34.下拉列表框的值:document.forms[0].selectName.options
.value (n有时用下拉列表框名称加上.selectedIndex来确定被选中的值)

35.字符串的定义:var myString = new String("This is lightsword");

36.字符串转成大写:string.toUpperCase(); 字符串转成小写:string.toLowerCase();

37.返回字符串2在字符串1中出现的位置:String1.indexOf("String2")!=-1则说明没找到.

38.取字符串中指定位置的一个字符:StringA.charAt(9);

39.取出字符串中指定起点和终点的子字符串:stringA.substring(2,6);

40. 数学函数:Math.PI(返回圆周率),Math.SQRT2(返回开方),Math.max(value1,value2)返回两个数中的最在值, Math.pow(value1,10)返回value1的十次方,Math.round(value1)四舍五入函数,Math.floor (Math.random()*(n+1))返回随机数

41.定义日期型变量:var today = new Date();

42.日 期函数列表:dateObj.getTime()得到时间,dateObj.getYear()得到年份,dateObj.getFullYear()得 到四位的年份,dateObj.getMonth()得到月份,dateObj.getDate()得到日,dateObj.getDay()得到日期 几,dateObj.getHours()得到小时,dateObj.getMinutes()得到分,dateObj.getSeconds()得到 秒,dateObj.setTime(value)设置时间,dateObj.setYear(val)设置年,dateObj.setMonth (val)设置月,dateObj.setDate(val)设置日,dateObj.setDay(val)设置星期几, dateObj.setHours设置小时,dateObj.setMinutes(val)设置分,dateObj.setSeconds(val)设 置秒 [注意:此日期时间从0开始计]

43.FRAME的表示方式: [window.]frames
.ObjFuncVarName,frames["frameName"].ObjFuncVarName,frameName.ObjFuncVarName

44.parent代表父亲对象,top代表最顶端对象

45.打开子窗口的父窗口为:opener

46.表示当前所属的位置:this

47.当在超链接中调用JS函数时用:(javascript :)来开头后面加函数名

48.在老的浏览器中不执行此JS:<!-- //-->

49.引用一个文件式的JS:<script type="text/javascript" src="aaa.js"></script>

50.指定在不支持脚本的浏览器显示的HTML:<noscript></noscript>

51. 当超链和onCLICK事件都有时,则老版本的浏览器转向a.html,否则转向b.html.例:<a href="a.html" onclick="location.href='b.html';return false">dfsadf</a>

52.JS 的内建对象有:Array,Boolean,Date,Error,EvalError,Function,Math,Number,Object, RangeError,ReferenceError,RegExp,String,SyntaxError,TypeError,URIError

53.JS中的换行:\n

54. 窗口全屏大小:<script>function fullScreen(){ this.moveTo(0,0);this.outerWidth=screen.availWidth;this.outerHeight=screen.availHeight;}window.maximize=fullScreen;</script>

55.JS中的all代表其下层的全部元素

56.JS中的焦点顺序:document.getElementByid("表单元素").tabIndex = 1

57.innerHTML 的值是表单元素的值:如<p id="para">"how are <em>you</em>"</p>,则innerHTML的值就是:how are <em>you</em>

58.innerTEXT的值和上面的一样,只不过不会把<em>这种标记显示出来.

59.contentEditable可设置元素是否可被修改,isContentEditable返回是否可修改的状态.

60.isDisabled判断是否为禁止状态.disabled设置禁止状态

61.length取得长度,返回整型数值

62.addBehavior()是一种JS调用的外部函数文件其扩展名为.htc

63.window.focus()使当前的窗口在所有窗口之前.

64.blur()指失去焦点.与FOCUS()相反.

65.select()指元素为选中状态.

66.防止用户对文本框中输入文本:onfocus="this.blur()"

67.取出该元素在页面中出现的数量:document.all.tags("div(或其它HTML标记符)").length

68.JS中分为两种窗体输出:模态和非模态.window.showModaldialog(),window.showModeless()

69.状态栏文字的设置:window.status='文字',默认的状态栏文字设置:window.defaultStatus = '文字.';

70.添加到收藏夹:external.AddFavorite("http://www.dannyg.com";,"jaskdlf");

71.JS中遇到脚本错误时不做任何操作:window.onerror = doNothing; 指定错误句柄的语法为:window.onerror = handleError;

72.JS中指定当前打开窗口的父窗口:window.opener,支持opener.opener...的多重继续.

73.JS中的self指的是当前的窗口

74.JS中状态栏显示内容:window.status="内容"

75.JS中的top指的是框架集中最顶层的框架

76.JS中关闭当前的窗口:window.close();

77.JS中提出是否确认的框:if(confirm("Are you sure?")){alert("ok");}else{alert("Not Ok");}

78.JS中的窗口重定向:window.navigate("http://www.sina.com.cn";);

79.JS中的打印:window.print()

80.JS中的提示输入框:window.prompt("message","defaultReply");

81.JS中的窗口滚动条:window.scroll(x,y)

82.JS中的窗口滚动到位置:window.scrollby

83.JS中设置时间间隔:setInterval("expr",msecDelay)或setInterval(funcRef,msecDelay)或setTimeout

84.JS中的模态显示在IE4+行,在NN中不行:showModalDialog("URL"[,arguments][,features]);

85.JS 中的退出之前使用的句柄:function verifyClose(){event.returnValue="we really like you and hope you will stay longer.";}} window.onbeforeunload=verifyClose;

86.当窗体第一次调用时使用的文件句柄:onload()

87.当窗体关闭时调用的文件句柄:onunload()

88.window.location 的属性: protocol(http:),hostname(www.example.com),port(80),host(www.example.com:80), pathname("/a/a.html"),hash("#giantGizmo",指跳转到相应的锚记),href(全部的信息)

89.window.location.reload()刷新当前页面.

90.window.history.back()返回上一页,window.history.forward()返回下一页,window.history.go(返回第几页,也可以使用访问过的URL)

91.document.write()不换行的输出,document.writeln()换行输出

92.document.body.noWrap=true;防止链接文字折行.

93.变量名.charAt(第几位),取该变量的第几位的字符.

94."abc".charCodeAt(第几个),返回第几个字符的ASCii码值.

95.字符串连接:string.concat(string2),或用+=进行连接

96.变量.indexOf("字符",起始位置),返回第一个出现的位置(从0开始计算)

97.string.lastIndexOf(searchString[,startIndex])最后一次出现的位置.

98.string.match(regExpression),判断字符是否匹配.

99.string.replace(regExpression,replaceString)替换现有字符串.

100.string.split(分隔符)返回一个数组存储值.

101.string.substr(start[,length])取从第几位到指定长度的字符串.

102.string.toLowerCase()使字符串全部变为小写.

103.string.toUpperCase()使全部字符变为大写.

104.parseInt(string[,radix(代表进制)])强制转换成整型.

105.parseFloat(string[,radix])强制转换成浮点型.

106.isNaN(变量):测试是否为数值型.

107.定义常量的关键字:const,定义变量的关键字:var

以下是对图像的介绍：

36 读取图像属性

1: <img src="/”image1.jpg"” name=”myImage”>

2: <a href=”# ” onClick=”window.alert(document.myImage.width)”>Width</a>

3:

37 动态加载图像

1: <script language=”JavaScript”>

2: myImage = new Image;

3: myImage.src = “Tellers1.jpg”;

4: </script>

38 简单的图像替换

1: <script language=”JavaScript”>

2: rollImage = new Image;

3: rollImage.src = “rollImage1.jpg”;

4: defaultImage = new Image;

5: defaultImage.src = “image1.jpg”;

6: </script>

7: <a href="/”myUrl"” onMouseOver=”document.myImage.src = rollImage.src;”

8: onMouseOut=”document.myImage.src = defaultImage.src;”>

9: <img src="/”image1.jpg"” name=”myImage” width=100 height=100 border=0>

39 随机显示图像

1: <script language=”JavaScript”>

2: var imageList = new Array;

3: imageList[0] = “image1.jpg”;

4: imageList[1] = “image2.jpg”;

5: imageList[2] = “image3.jpg”;

6: imageList[3] = “image4.jpg”;

7: var imageChoice = Math.floor(Math.random() * imageList.length);

8: document.write(‘<img src=”’ + imageList[imageChoice] + ‘“>’);

9: </script>

40 函数实现的图像替换

1: <script language=”JavaScript”>

2: var source = 0;

3: var replacement = 1;

4: function createRollOver(originalImage,replacementImage) {

5: var imageArray = new Array;

6: imageArray[source] = new Image;

7: imageArray[source].src = originalImage;

8: imageArray[replacement] = new Image;

9: imageArray[replacement].src = replacementImage;

10: return imageArray;

11: }

12: var rollImage1 = createRollOver(“image1.jpg”,”rollImage1.jpg”);

13: </script>

14: <a href=”#” onMouseOver=”document.myImage1.src = rollImage1[replacement].src;”

15: onMouseOut=”document.myImage1.src = rollImage1[source].src;”>

16: <img src="/”image1.jpg"” width=100 name=”myImage1” border=0>

17: </a>

41 创建幻灯片

1: <script language=”JavaScript”>

2: var imageList = new Array;

3: imageList[0] = new Image;

4: imageList[0].src = “image1.jpg”;

5: imageList[1] = new Image;

6: imageList[1].src = “image2.jpg”;

7: imageList[2] = new Image;

8: imageList[2].src = “image3.jpg”;

9: imageList[3] = new Image;

10: imageList[3].src = “image4.jpg”;

11: function slideShow(imageNumber) {

12: document.slideShow.src = imageList[imageNumber].src;

13: imageNumber += 1;

14: if (imageNumber < imageList.length) {

15: window.setTimeout(“slideShow(“ + imageNumber + “)”,3000);

16: }

17: }

18: </script>

19: </head>

20: <body onLoad=”slideShow(0)”>

21: <img src="/”image1.jpg"” width=100 name=”slideShow”>

42 随机广告图片

1: <script language=”JavaScript”>

2: var imageList = new Array;

3: imageList[0] = “image1.jpg”;

4: imageList[1] = “image2.jpg”;

5: imageList[2] = “image3.jpg”;

6: imageList[3] = “image4.jpg”;

7: var urlList = new Array;

8: urlList[0] = “http://some.host/”;

9: urlList[1] = “http://another.host/”;

10: urlList[2] = “http://somewh/ere.else/”;

11: urlList[3] = “http://right.here/”;

12: var imageChoice = Math.floor(Math.random() * imageList.length);

13: document.write(‘<a href=”’ + urlList[imageChoice] + ‘“><img src=”’ + imageList[imageChoice] + ‘“></a>’);

14: </script>

JavaScript就这么回事4：表单

还是先继续写完JS就这么回事系列吧～

43 表单构成

1: <form method=”post” action=”target.html” name=”thisForm”>

2: <input type=”text” name=”myText”>

3: <select name=”mySelect”>

4: <option value=”1”>First Choice</option>

5: <option value=”2”>Second Choice</option>

6: </select>

7: <br>

8: <input type=”submit” value=”Submit Me”>

9: </form>

44 访问表单中的文本框内容

1: <form name=”myForm”>

2: <input type=”text” name=”myText”>

3: </form>

4: <a href='#' onClick='window.alert(document.myForm.myText.value);'>Check Text Field</a>

45 动态复制文本框内容

1: <form name=”myForm”>

2: Enter some Text: <input type=”text” name=”myText”><br>

3: Copy Text: <input type=”text” name=”copyText”>

4: </form>

5: <a href=”#” onClick=”document.myForm.copyText.value =

6: document.myForm.myText.value;”>Copy Text Field</a>

46 侦测文本框的变化

1: <form name=”myForm”>

2: Enter some Text: <input type=”text” name=”myText” onChange=”alert(this.value);”>

3: </form>

47 访问选中的Select

1: <form name=”myForm”>

2: <select name=”mySelect”>

3: <option value=”First Choice”>1</option>

4: <option value=”Second Choice”>2</option>

5: <option value=”Third Choice”>3</option>

6: </select>

7: </form>

8: <a href='#' onClick='alert(document.myForm.mySelect.value);'>Check Selection List</a>

48 动态增加Select项

1: <form name=”myForm”>

2: <select name=”mySelect”>

3: <option value=”First Choice”>1</option>

4: <option value=”Second Choice”>2</option>

5: </select>

6: </form>

7: <script language=”JavaScript”>

8: document.myForm.mySelect.length++;

9: document.myForm.mySelect.options[document.myForm.mySelect.length - 1].text = “3”;

10: document.myForm.mySelect.options[document.myForm.mySelect.length - 1].value = “Third Choice”;

11: </script>

49 验证表单字段

1: <script language=”JavaScript”>

2: function checkField(field) {

3: if (field.value == “”) {

4: window.alert(“You must enter a value in the field”);

5: field.focus();

6: }

7: }

8: </script>

9: <form name=”myForm” action=”target.html”>

10: Text Field: <input type=”text” name=”myField”onBlur=”checkField(this)”>

11: <br><input type=”submit”>

12: </form>

50 验证Select项

1: function checkList(selection) {

2: if (selection.length == 0) {

3: window.alert(“You must make a selection from the list.”);

4: return false;

5: }

6: return true;

7: }

51 动态改变表单的action

1: <form name=”myForm” action=”login.html”>

2: Username: <input type=”text” name=”username”><br>

3: Password: <input type=”password” name=”password”><br>

4: <input type=”button” value=”Login” onClick=”this.form.submit();”>

5: <input type=”button” value=”Register” onClick=”this.form.action = ‘register.html’; this.form.submit();”>

6: <input type=”button” value=”Retrieve Password” onClick=”this.form.action = ‘password.html’; this.form.submit();”>

7: </form>

52 使用图像按钮

1: <form name=”myForm” action=”login.html”>

2: Username: <input type=”text” name=”username”><br>

3: Password: <input type=”password”name=”password”><br>

4: <input type=”image” src="/”login.gif"” value=”Login”>

5: </form>

6:

53 表单数据的加密

1: <SCRIPT LANGUAGE='JavaScript'>

2: <!--

3: function encrypt(item) {

4: var newItem = '';

5: for (i=0; i < item.length; i++) {

6: newItem += item.charCodeAt(i) + '.';

7: }

8: return newItem;

9: }

10: function encryptForm(myForm) {

11: for (i=0; i < myForm.elements.length; i++) {

12: myForm.elements[i].value = encrypt(myForm.elements[i].value);

13: }

14: }

15:

16: //-->

17: </SCRIPT>

18: <form name='myForm' onSubmit='encryptForm(this); window.alert(this.myField.value);'>

19: Enter Some Text: <input type=text name=myField><input type=submit>

20: </form>

JavaScript就这么回事5：窗口和框架

54 改变浏览器状态栏文字提示

1: <script language=”JavaScript”>

2: window.status = “A new status message”;

3: </script>

55 弹出确认提示框

1: <script language=”JavaScript”>

2: var userChoice = window.confirm(“Click OK or Cancel”);

3: if (userChoice) {

4: document.write(“You chose OK”);

5: } else {

6: document.write(“You chose Cancel”);

7: }

8: </script>

56 提示输入

1: <script language=”JavaScript”>

2: var userName = window.prompt(“Please Enter Your Name”,”Enter Your Name Here”);

3: document.write(“Your Name is “ + userName);

4: </script>

57 打开一个新窗口

1: //打开一个名称为myNewWindow的浏览器新窗口

2: <script language=”JavaScript”>

3: window.open(“http://www.handandaily.com/”,”myNewWindow”);

4: </script>

58 设置新窗口的大小

1: <script language=”JavaScript”>

2: window.open(“http://www.handandaily.com/”,”myNewWindow”,'height=300,width=300');

3: </script>

59 设置新窗口的位置

1: <script language=”JavaScript”>

2: window.open(“http://www.handandaily.com/”,”myNewWindow”,'height=300,width=300,left=200,screenX=200,top=100,screenY=100');

3: </script>

60 是否显示工具栏和滚动栏

1: <script language=”JavaScript”>

2: window.open(“http:

61 是否可以缩放新窗口的大小

1: <script language=”JavaScript”>

2: window.open('http://www.handandaily.com/' , 'myNewWindow', 'resizable=yes' );</script>

62 加载一个新的文档到当前窗口

1: <a href='#' onClick='document.location = '125a.html';' >Open New Document</a>

63 设置页面的滚动位置

1: <script language=”JavaScript”>

2: if (document.all) { //如果是IE浏览器则使用scrollTop属性

3: document.body.scrollTop = 200;

4: } else { //如果是NetScape浏览器则使用pageYOffset属性

5: window.pageYOffset = 200;

6: }</script>

64 在IE中打开全屏窗口

1: <a href='#' onClick=”window.open('http://www.handandaily.com/','newWindow','fullScreen=yes');”>Open a full-screen window</a>

65 新窗口和父窗口的操作

1: <script language=”JavaScript”>

2: //定义新窗口

3: var newWindow = window.open(“128a.html”,”newWindow”);

4: newWindow.close(); //在父窗口中关闭打开的新窗口

5: </script>

6: 在新窗口中关闭父窗口

7: window.opener.close()

66 往新窗口中写内容

1: <script language=”JavaScript”>

2: var newWindow = window.open(“”,”newWindow”);

3: newWindow.document.open();

4: newWindow.document.write(“This is a new window”);

5: newWIndow.document.close();

6: </script>

67 加载页面到框架页面

1: <frameset cols=”50%,*”>

2: <frame name=”frame1” src="/”135a.html"”>

3: <frame name=”frame2” src="/”about:blank"”>

4: </frameset>

5: 在frame1中加载frame2中的页面

6: parent.frame2.document.location = “135b.html”;

68 在框架页面之间共享脚本

如果在frame1中html文件中有个脚本

1: function doAlert() {

2: window.alert(“Frame 1 is loaded”);

3: }

那么在frame2中可以如此调用该方法

1: <body onLoad=”parent.frame1.doAlert();”>

2: This is frame 2.

3: </body>

69 数据公用

可以在框架页面定义数据项，使得该数据可以被多个框架中的页面公用

1: <script language=”JavaScript”>

2: var persistentVariable = “This is a persistent value”;

3: </script>

4: <frameset cols=”50%,*”>

5: <frame name=”frame1” src="/”138a.html"”>

6: <frame name=”frame2” src="/”138b.html"”>

7: </frameset>

这样在frame1和frame2中都可以使用变量persistentVariable

70 框架代码库

根据以上的一些思路，我们可以使用一个隐藏的框架页面来作为整个框架集的代码库

1: <frameset cols=”0,50%,*”>

2: <frame name=”codeFrame” src="/”140code.html"”>

3: <frame name=”frame1” src="/”140a.html"”>

4: <frame name=”frame2” src="/”140b.html"”>

5: </frameset>