JavaScript的方法和技巧

简介:
摘自 http://www.cnblogs.com/Jamedy/archive/2007/02/14/650079.html

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,就像崇拜所有OOP语言一样~
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(“&”);
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="/”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.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: 


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> 



    本文转自永春博客园博客,原文链接:http://www.cnblogs.com/firstyi/archive/2007/02/14/650097.html,如需转载请自行联系原作者



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