JavaScript语法大全

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JavaScript 方法和技巧大全

1 创建脚本块

JavaScript code goes here

</script>

2 隐藏脚本代码

</script>

在不支持 JavaScript 的浏览器中将不执行相关代码

3 浏览器不支持的时候显示

Hello to the non-JavaScript browser.

</noscript>

4 链接外部脚本文件

5 注释脚本

// This is a comment document.write(“Hello”);

// This is a comment

/**All of this is a comment */

6 输出到浏览器

document.write(“<strong>Hello</strong>”);

7 定义变量

var myVariable = “some value”;

8 字符串相加

var myString = “String1” + “String2”;

9 字符串搜索

<!-var myVariable = “Hello there”; var therePlace = myVariable.search(“there”); document.write(therePlace); // -->

</script>

10 字符串替换

thisVar.replace(“Monday”,”Friday”);

11 格式化字串

<!-

var myVariable = “Hello there”; document.write(myVariable.big() + “<br>”);

document.write(myVariable.blink() + “<br>”);

document.write(myVariable.bold() + “<br>”);

document.write(myVariable.fixed() + “<br>”);

document.write(myVariable.fontcolor(“red”) + “<br>”);

document.write(myVariable.fontsize(“18pt”) + “<br>”);

document.write(myVariable.italics() + “<br>”);

document.write(myVariable.small() + “<br>”);

document.write(myVariable.strike() + “<br>”);

document.write(myVariable.sub() + “<br>”);

document.write(myVariable.sup() + “<br>”);

document.write(myVariable.toLowerCase() + “<br>”);

document.write(myVariable.toUpperCase() + “<br>”);

var firstString = “My String”;

var finalString = firstString.bold().toLowerCase().fontcolor(“red”);

-->

</script>

12 创建数组

<!-

var myArray = new Array(5);

myArray[0] = “First Entry”;

myArray[1] = “Second Entry”;

myArray[2] = “Third Entry”;

myArray[3] = “Fourth Entry”;

myArray[4] = “Fifth Entry”;

var anotherArray = new Array(“First Entry”,”Second Entry”,”Third Entry”,”Fourth Entry”,”Fifth Entry”);

-->

</script>

13 数组排序

<!--

var myArray = new Array(5);

myArray[0] = “z”;

myArray[1] = “c”;

myArray[2] = “d”;

myArray[3] = “a”;

myArray[4] = “q”;

document.write(myArray.sort());

-->

</script>

14 分割字符串

<!--

var myVariable = “a,b,c,d”;

var stringArray = myVariable.split(“,”);

document.write(stringArray[0]);

document.write(stringArray[1]);

document.write(stringArray[2]);

document.write(stringArray[3]);

-->

</script>

15 弹出警告信息 1: 2: 3: 4: 5: <script language=”JavaScript”> <!-window.alert(“Hello”); // --> </script>
16 弹出确认框 1: 2: 3: 4: 5: <script language=”JavaScript”> <!-var result = window.confirm(“Click OK to continue”); // --> </script>
17 定义函数
1: 2: 3: 4: 5: 6: 7: 8:
<script language=”JavaScript”> <!-function multiple(number1,number2) { var result = number1 * number2; return result; } // --> </script>
18 调用 JS 函数 1: <a href=”#” onClick=”functionName()”>Link text</a> 2: <a href="/”javascript:functionName"()”>Link text</a>
19 在页面加载完成后执行函数 1: <body onLoad=”functionName();”> 2: Body of the page 3: </body>
20 条件判断 1: 2: 3: 4: 5: 6: 7: <script> <!-var userChoice = window.confirm(“Choose OK or Cancel”); var result = (userChoice == true) ? “OK” : “Cancel”; document.write(result); // --> </script>
21 指定次数循环 1: 2: 3: 4: <script> <!-var myArray = new Array(3); myArray[0] = “Item 0”;
5: myArray[1] = “Item 1”; 6: myArray[2] = “Item 2”; 7: for (i = 0; i < myArray.length; i++) { 8: document.write(myArray[i] + “<br>”); 9: } 10: // --> 11: </script>
22 设定将来执行 1: 2: 3: 4: 5: 6: 7: 8: <script> <!-function hello() { window.alert(“Hello”); } window.setTimeout(“hello()”,5000); // --> </script>
23 定时执行函数 1: 2: 3: 4: 5: 6: 7: 8: 9: <script> <!-function hello() { window.alert(“Hello”); window.setTimeout(“hello()”,5000); } window.setTimeout(“hello()”,5000); // --> </script>
24 取消定时执行 1: 2: 3: 4: 5: <script> <!-function hello() { window.alert(“Hello”); }
6: 7: 8: 9:
var myTimeout = window.setTimeout(“hello()”,5000); window.clearTimeout(myTimeout); // --> </script>
25 在页面卸载时候执行函数 1: <body onUnload=”functionName();”> 2: Body of the page 3: </body> JavaScript 就这么回事 2：浏览器输出
26 访问 document 对象 1: 2: 3: 4: <script language=”JavaScript”> var myURL = document.URL; window.alert(myURL); </script>
27 动态输出 HTML 1: <script language=”JavaScript”> 2: document.write(“<p>Here’s some information about this document:</p>”); 3: document.write(“<ul>”); 4: document.write(“<li>Referring Document: “ + document.referrer + “</li>”); 5: document.write(“<li>Domain: “ + document.domain + “</li>”); 6: document.write(“<li>URL: “ + document.URL + “</li>”); 7: document.write(“</ul>”); 8: </script>
28 输出换行 1: document.writeln(“<strong>a</strong>”); 2: document.writeln(“b”);
29 输出日期 1: 2: 3: 4: <script language=”JavaScript”> var thisDate = new Date(); document.write(thisDate.toString()); </script>
30 指定日期的时区 1: <script language=”JavaScript”> 2: var myOffset = -2; 3: var currentDate = new Date(); 4: var userOffset = currentDate.getTimezoneOffset()/60; 5: var timeZoneDifference = userOffset - myOffset; 6: currentDate.setHours(currentDate.getHours() + timeZoneDifference); 7: document.write(“The time and date in Central Europe is: “ + currentDate.toLocaleString()); 8: </script>
31 设置日期输出格式 1: <script language=”JavaScript”> 2: var thisDate = new Date(); 3: var thisTimeString = thisDate.getHours() + “:” + thisDate.getMinutes(); 4: var thisDateString = thisDate.getFullYear() + “/” + thisDate.getMonth() + “/” + thisDate.getDate(); 5: document.write(thisTimeString + “ on “ + thisDateString); 6: </script>
32 读取 URL 参数 1: 2: 3: 4: 5: 6: 7: <script language=”JavaScript”> var urlParts = document.URL.split(“?”); var parameterParts = urlParts[1].split(“&”); for (i = 0; i < parameterParts.length; i++) { var pairParts = parameterParts[i].split(“=”); var pairName = pairParts[0]; var pairValue = pairParts[1];
8: document.write(pairName + “ ：“ +pairValue ); 9: } 10: </script> 你还以为 HTML 是无状态的么？ 33 打开一个新的 document 对象 1: 2: 3: 4: 5: 6: 7: <script language=”JavaScript”> function newDocument() { document.open(); document.write(“<p>This is a New Document.</p>”); document.close(); } </script>
34 页面跳转 1: <script language=”JavaScript”> 2: window.location = “http://www.liu21st.com/”; 3: </script>
35 添加网页加载进度窗口 1: <html> 2: <head> 3: <script language='javaScript'> 4: var placeHolder = window.open('holder.html','placeholder','width=200,height=200'); 5: </script> 6: <title>The Main Page</title> 7: </head> 8: <body onLoad='placeHolder.close()'> 9: <p>This is the main page</p> 10: </body> 11: </html>
JavaScript 就这么回事 3：图像
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: 2: 3: 4: <script language=”JavaScript”> myImage = new Image; myImage.src = “Tellers1.jpg”; </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: 2: 3: 4: 5: 6: 7: 8: <script language=”JavaScript”> var imageList = new Array; imageList[0] = “image1.jpg”; imageList[1] = “image2.jpg”; imageList[2] = “image3.jpg”; imageList[3] = “image4.jpg”; var imageChoice = Math.floor(Math.random() * imageList.length); 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: 19: 20: 21:
</script> </head> <body onLoad=”slideShow(0)”> <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://somewhere.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: 2: 3: 4: 5: 6: 7: 8: 9: <form method=”post” action=”target.html” name=”thisForm”> <input type=”text” name=”myText”> <select name=”mySelect”> <option value=”1”>First Choice</option> <option value=”2”>Second Choice</option> </select> <br> <input type=”submit” value=”Submit Me”> </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: 2: 3: 4: 5: 6: <form name=”myForm”> Enter some Text: <input type=”text” name=”myText”><br> Copy Text: <input type=”text” name=”copyText”> </form> <a href=”#” onClick=”document.myForm.copyText.value = document.myForm.myText.value;”>Copy Text Field</a>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: 2: 3: 4: <form name=”myForm”> <select name=”mySelect”> <option value=”First Choice”>1</option> <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: 2: 3: 4: 5: 6: 7: function checkList(selection) { if (selection.length == 0) { window.alert(“You must make a selection from the list.”); return false; } return true; }
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: 2: 3: 4: 5: 6: <form name=”myForm” action=”login.html”> Username: <input type=”text” name=”username”><br> Password: <input type=”password”name=”password”><br> <input type=”image” src="/”login.gif"” value=”Login”> </form>
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: 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>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: 2: 3: 4: 5: 6: 7: <script language=”JavaScript”> var persistentVariable = “This is a persistent value”; </script> <frameset cols=”50%,*”> <frame name=”frame1” src="/”138a.html"”> <frame name=”frame2” src="/”138b.html"”> </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: 2: 3: 4: 5: <frameset cols=”0,50%,*”> <frame name=”codeFrame” src="/”140code.html"”> <frame name=”frame1” src="/”140a.html"”> <frame name=”frame2” src="/”140b.html"”> </frameset
55 弹出确认提示框 1: 2: 3: 4: 5: 6: 7: 8: <script language=”JavaScript”> var userChoice = window.confirm(“Click OK or Cancel”); if (userChoice) { document.write(“You chose OK”); } else { document.write(“You chose Cancel”); } </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: 2: 3: 4: //打开一个名称为 myNewWindow 的浏览器新窗口 <script language=”JavaScript”> window.open(“http://www.liu21st.com/”,”myNewWindow”); </script>
58 设置新窗口的大小
1: <script language=”JavaScript”> 2: window.open(“http://www.liu21st.com/”,”myNewWindow”,'height=300,wi dth=300'); 3: </script>
59 设置新窗口的位置 1: <script language=”JavaScript”> 2: window.open(“http://www.liu21st.com/”,”myNewWindow”,'height=300,wi dth=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.liu21st.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: 2: 3: 4: 5: 6: <script language=”JavaScript”> if (document.all) { //如果是 IE 浏览器则使用 scrollTop 属性 document.body.scrollTop = 200; } else { //如果是 NetScape 浏览器则使用 pageYOffset 属性 window.pageYOffset = 200; }</script>
64 在 IE 中打开全屏窗口 1: <a href='#' onClick=”window.open('http://www.juxta.com/','newWindow','fullScreen= yes');”>Open a full-screen window</a>
65 新窗口和父窗口的操作 1: 2: 3: 4: 5: 6: 7: <script language=”JavaScript”> //定义新窗口 var newWindow = window.open(“128a.html”,”newWindow”); newWindow.close(); //在父窗口中关闭打开的新窗口 </script> 在新窗口中关闭父窗口 window.opener.close()
66 往新窗口中写内容 1: 2: 3: 4: 5: 6: <script language=”JavaScript”> var newWindow = window.open(“”,”newWindow”); newWindow.document.open(); newWindow.document.write(“This is a new window”); newWIndow.document.close(); </script>
67 加载页面到框架页面 1: 2: 3: 4: 5: 6: <frameset cols=”50%,*”> <frame name=”frame1” src="/”135a.html"”> <frame name=”frame2” src="/”about:blank"”> </frameset> 在 frame1 中加载 frame2 中的页面 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
46 侦测文本框的