JavaScript使用技巧

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1 创建脚本块

1: <  script language=”JavaScript”>2: JavaScript code goes here3: </ script>

2 隐藏脚本代码

1: < script language=”JavaScript”>2: <!--3: document.write(“Hello”);4: // -->5: <  /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

1: <noscript>2: Hello to the non-JavaScript browser.3: </noscript>

4 链接外部脚本文件

1: <script language=”JavaScript” src="/”filename.js"”></script>

5 注释脚本

1: // This is a comment2: document.write(“Hello”); // This is a comment3: /*4: All of this5: is a comment6: */

6 输出到浏览器

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

7 定义变量

1: var myVariable = “some value”;

8 字符串相加

1: var myString = “String1” + “String2”;

9 字符串搜索

1: <script language=”JavaScript”>2: <!--3: var myVariable = “Hello there”;4: var therePlace = myVariable.search(“there”);5: document.write(therePlace);6: // -->7: </script>

10 字符串替换

1: thisVar.replace(“Monday”,”Friday”);

11 格式化字串

1: <script language=”JavaScript”>2: <!--3: var myVariable = “Hello there”;4: document.write(myVariable.big() + “<br>”);5: document.write(myVariable.blink() + “<br>”);6: document.write(myVariable.bold() + “<br>”);7: document.write(myVariable.fixed() + “<br>”);8: document.write(myVariable.fontcolor(“red”) + “<br>”);9: document.write(myVariable.fontsize(“18pt”) + “<br>”);10: document.write(myVariable.italics() + “<br>”);11: document.write(myVariable.small() + “<br>”);12: document.write(myVariable.strike() + “<br>”);13: document.write(myVariable.sub() + “<br>”);14: document.write(myVariable.sup() + “<br>”);15: document.write(myVariable.toLowerCase() + “<br>”);16: document.write(myVariable.toUpperCase() + “<br>”);17: 18: var firstString = “My String”;19: var finalString = firstString.bold().toLowerCase().fontcolor(“red”);20: // -->21: </script>

12 创建数组

1: <script language=”JavaScript”>2: <!--3: var myArray = new Array(5);4: myArray[0] = “First Entry”;5: myArray[1] = “Second Entry”;6: myArray[2] = “Third Entry”;7: myArray[3] = “Fourth Entry”;8: myArray[4] = “Fifth Entry”;9: var anotherArray = new Array(“First Entry”,”Second Entry”,”Third Entry”,”Fourth Entry”,”Fifth Entry”);10: // -->11: </script>

13 数组排序

1: <script language=”JavaScript”>2: <!--3: var myArray = new Array(5);4: myArray[0] = “z”;5: myArray[1] = “c”;6: myArray[2] = “d”;7: myArray[3] = “a”;8: myArray[4] = “q”;9: document.write(myArray.sort());10: // -->11: </script>

14 分割字符串

1: <script language=”JavaScript”>2: <!--3: var myVariable = “a,b,c,d”;4: var stringArray = myVariable.split(“,”);5: document.write(stringArray[0]);6: document.write(stringArray[1]);7: document.write(stringArray[2]);8: document.write(stringArray[3]);9: // -->10: </script>

15 弹出警告信息

1: <script language=”JavaScript”>2: <!--3: window.alert(“Hello”);4: // -->5: </script>

16 弹出确认框

1: <script language=”JavaScript”>2: <!--3: var result = window.confirm(“Click OK to continue”);4: // -->5: </script>

17 定义函数

1: <script language=”JavaScript”>2: <!--3: function multiple(number1,number2) { 4: var result = number1 * number2;5: return result;6: }7: // -->8: </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 page3: </body>

20 条件判断

1: <script>2: <!--3: var userChoice = window.confirm(“Choose OK or Cancel”);4: var result = (userChoice == true) ? “OK” : “Cancel”;5: document.write(result);6: // -->7: </script>

21 指定次数循环

1: <script>2: <!--3: var myArray = new Array(3);4: 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: <script>2: <!--3: function hello() { 4: window.alert(“Hello”);5: }6: window.setTimeout(“hello()”,5000);7: // -->8: </script>

23 定时执行函数

1: <script>2: <!--3: function hello() { 4: window.alert(“Hello”);5: window.setTimeout(“hello()”,5000);6: }7: window.setTimeout(“hello()”,5000);8: // -->9: </script>

24 取消定时执行

1: <script>2: <!--3: function hello() { 4: window.alert(“Hello”);5: }6: var myTimeout = window.setTimeout(“hello()”,5000);7: window.clearTimeout(myTimeout);8: // -->9: </script>

25 在页面卸载时候执行函数

1: <body onUnload=”functionName();”>2: Body of the page3: </body>

JavaScript就这么回事2：浏览器输出

26 访问document对象

1: <script language=”JavaScript”>2: var myURL = document.URL;3: window.alert(myURL);4: </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: <script language=”JavaScript”>2: var thisDate = new Date();3: document.write(thisDate.toString());4: </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: <script language=”JavaScript”>2: var urlParts = document.URL.split(“?”);3: var parameterParts = urlParts[1].split(“&”);4: for (i = 0; i < parameterParts.length; i++) { 5: var pairParts = parameterParts[i].split(“=”);6: var pairName = pairParts[0];7: 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: <script language=”JavaScript”>2: function newDocument() { 3: document.open();4: document.write(“<p>This is a New Document.</p>”);5: document.close();6: }7: </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="http://www.knowsky.com/”image1.jpg"” name=”myImage”>2: <a href=”# ” onClick=”window.alert(document.myImage.width)”>Width</a>

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="http://www.knowsky.com/”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="http://www.knowsky.com/”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="http://www.knowsky.com/”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: <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="http://www.knowsky.com/”login.gif"” value=”Login”>5: </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: </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.liu21st.com/”,”myNewWindow”);4: </script>

58 设置新窗口的大小

1: <script language=”JavaScript”>2: window.open(“http://www.liu21st.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.liu21st.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://baidu.com");

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: <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.juxta.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>

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