JavaScript的方法和技巧

 这篇介绍javascript方面的日志，我在是Clang上看到的。作者介绍挺全面的，所以转载过来让感兴趣的朋友看一下。呵呵～～～ 


有些时候你精通一门语言，但是会发现你其实整天在和其它语言打交道，也许你以为这些微不足道，不至于影响你的开发进度，但恰恰是这些你不重视的东西会浪费你很多时间，我一直以为我早在几年前就已经精通JavaScript了，直到目前，我才越来越觉得JavaScript远比我想象的复杂和强大，我开始崇拜它， 
趁着节日的空隙，把有关JavaScript的方法和技巧整理下，让每个在为JavaScript而烦恼的人明白，JavaScript就这么回事！并希望JavaScript还可以成为你的朋友，让你豁然开朗，在项目中更好的应用～ 

适合阅读范围：对JavaScript一无所知～离精通只差一步之遥的人 
基础知识：HTML 
JavaScript就这么回事1：基础知识 


1 创建脚本块 
1: <script language=”JavaScript” > 
2: JavaScript code goes here 
3: </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 comment 
2: document.write(“Hello”); // This is a comment 
3: /* 
4: All of this 
5: is a comment 
6: */ 

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 page 
3: </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 page 
3: </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(“&amp;amp;”); 
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= &amp;amp;apos;javaScript &amp;amp;apos; > 
4: var placeHolder = window.open( &amp;amp;apos;holder.html &amp;amp;apos;, &amp;amp;apos;placeholder &amp;amp;apos;, &amp;amp;apos;width=200,height=200 &amp;amp;apos;); 
5: </script > 
6: <title >The Main Page </title > 
7: </head > 
8: <body   onLoad= &amp;amp;apos;placeHolder.close() &amp;amp;apos; > 
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: <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://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= &amp;amp;apos;# &amp;amp;apos; onClick= &amp;amp;apos;window.alert(document.myForm.myText.value); &amp;amp;apos; >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= &amp;amp;apos;# &amp;amp;apos; onClick= &amp;amp;apos;alert(document.myForm.mySelect.value); &amp;amp;apos; >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: }
posted @ 2009-04-29 20:21  小宇飞刀  阅读(141)  评论(0)  编辑  收藏  举报