JavaScript／js脚本实现各种页面处理功能基础知识大集

12月 24, 2021 / 程序员

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

JavaScript就这么回事1：基础知识

1 创建脚本块

<script language=”JavaScript”>
JavaScript code goes here
</script>
2 隐藏脚本代码

<script language=”JavaScript”>
<!–
document.write(“Hello”);
// –>
</script>
3 在不支持JavaScript的浏览器中将不执行相关代码,浏览器不支持的时候显示

<noscript>
Hello to the non-JavaScript browser.
</noscript>
4 链接外部脚本文件

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

<script language=”JavaScript”>
<!–
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

<script language=”JavaScript”>
<!–
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

<script language=”JavaScript”>
<!–
var myArray = new Array(4);
myArray[0] = “First Entry”;
myArray[1] = “Second Entry”;
myArray[2] = “Third Entry”;
myArray[3] = “Fourth Entry”;
var anotherArray = new Array(“First Entry”,”Second Entry”,”Third Entry”,”Fourth Entry”);
// –>
</script>

13 数组排序

<script language=”JavaScript”>
<!–
var myArray = new Array(4);
myArray[0] = “z”;
myArray[1] = “c”;
myArray[2] = “d”;
myArray[3] = “a”;
document.write(myArray.sort());
// –>
</script>
14 分割字符串

<script language=”JavaScript”>
<!–
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

<script language=”JavaScript”>
<!–
window.alert(“Hello”);
// –>
</script>

16 弹出确认框

<script language=”JavaScript”>
<!–
var result = window.confirm(“Click OK to continue”);
// –>
</script>
17 定义函数

<script language=”JavaScript”>
<!–
function multiple(number1,number2) {
var result = number1 * number2;
return result;
}
// –>
</script>
18 调用JS函数

<a href=”#” onClick=”functionName()”>Link text</a>
<a href=”javascript:functionName()”>Link text</a>
19 在页面加载完成后执行函数

<body onLoad=”functionName();”>
Body of the page
</body>
20 条件判断

<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

<script>
<!–
var myArray = new Array(3);
myArray[0] = “Item 0″;
myArray[1] = “Item 1″;
myArray[2] = “Item 2″;
for (i = 0; i < myArray.length; i++) {
document.write(myArray + “<br>”);
}
// –>
</script>
22 设定将来执行,延时5秒

<script>
<!–
function hello() {
window.alert(“Hello”);
}
window.setTimeout(“hello()”,5000);
// –>
</script>
23 定时执行函数

<script>
<!–
function hello() {
window.alert(“Hello”);
window.setTimeout(“hello()”,5000);
}
hello();
// –>
</script>
24 取消定时执行

<script>
<!–
function hello() {
window.alert(“Hello”);
}
var myTimeout = window.setTimeout(“hello()”,5000);
window.clearTimeout(myTimeout);
// –>
</script>
25 在页面卸载时候执行函数

<body onUnload=”functionName();”>
Body of the page
</body>

avaScript就这么回事2：浏览器输出

26 访问document对象

<script language=”JavaScript”>
var myURL = document.URL;
window.alert(myURL);
</script>
27 动态输出HTML

<script language=”JavaScript”>
document.write(“<p>Here’s some information about this document:</p>”);
document.write(“<ul>”);
document.write(“<li>Referring Document: ” + document.referrer + “</li>”);
document.write(“<li>Domain: ” + document.domain + “</li>”);
document.write(“<li>URL: ” + document.URL + “</li>”);
document.write(“</ul>”);
</script>
28 输出换行

document.writeln(“<strong>a</strong>”);
document.writeln(“b”);
29 输出日期

<script language=”JavaScript”>
var thisDate = new Date();
document.write(thisDate.toString());
</script>
30 指定日期的时区

<script language=”JavaScript”>
var myOffset = -2;
var currentDate = new Date();
var userOffset = currentDate.getTimezoneOffset()/60;
var timeZoneDifference = userOffset – myOffset;
currentDate.setHours(currentDate.getHours() + timeZoneDifference);
document.write(“The time and date in Central Europe is: ” + currentDate.toLocaleString());
</script>
31 设置日期输出格式

<script language=”JavaScript”>
var thisDate = new Date();
var thisTimeString = thisDate.getHours() + “:” + thisDate.getMinutes();
var thisDateString = thisDate.getFullYear() + “/” + thisDate.getMonth() + “/” + thisDate.getDate();
document.write(thisTimeString + ” on ” + thisDateString);
</script>
32 读取URL参数，你还以为HTML是无状态的么？

<script language=”JavaScript”>
var urlParts = document.URL.split(“?”);
var parameterParts = urlParts[1].split(“&”);
for (i = 0; i < parameterParts.length; i++) {
var pairParts = parameterParts.split(“=”);
var pairName = pairParts[0];
var pairValue = pairParts[1];
document.write(pairName + ” ：” +pairValue );
}
</script>
33 打开一个新的document对象

<script language=”JavaScript”>
function newDocument() {
document.open();
document.write(“<p>This is a New Document.</p>”);
document.close();
}
</script>
34 页面跳转

<script language=”JavaScript”>
window.location = “http://www.skyonsea.com/”;
</script>
35 添加网页加载进度窗口

<html>
<head>
<script language=’javaScript’>
var placeHolder = window.open(‘holder.html’,’placeholder’,’width=200,height=200′);
</script>
<title>The Main Page</title>
</head>
<body onLoad=’placeHolder.close()’>
<p>This is the main page</p>
</body>
</html>

avaScript就这么回事3：图像

36 读取图像属性

<img src=”/”image1.jpg”” name=”myImage”>
<a href=”#” onClick=”window.alert(document.myImage.width)”>Width</a>
37 动态加载图像

<script language=”JavaScript”>
myImage = new Image;
myImage.src = “Tellers1.jpg”;
</script>
38 简单的图像替换

<script language=”JavaScript”>
rollImage = new Image;
rollImage.src = “rollImage1.jpg”;
defaultImage = new Image;
defaultImage.src = “image1.jpg”;
</script>
<a href=”/”myUrl”” onMouseOver=”document.myImage.src = rollImage.src;”
onMouseOut=”document.myImage.src = defaultImage.src;”>
<img src=”/”image1.jpg”” name=”myImage” width=100 height=100 border=0>
39 随机显示图像

<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] + ‘”>’);
</script>
40 函数实现的图像替换

<script language=”JavaScript”>
var source = 0;
var replacement = 1;
function createRollOver(originalImage,replacementImage) {
var imageArray = new Array;
imageArray[source] = new Image;
imageArray[source].src = originalImage;
imageArray[replacement] = new Image;
imageArray[replacement].src = replacementImage;
return imageArray;
}
var rollImage1 = createRollOver(“image1.jpg”,”rollImage1.jpg”);
</script>
<a href=”#” onMouseOver=”document.myImage1.src = rollImage1[replacement].src;”
onMouseOut=”document.myImage1.src = rollImage1[source].src;”>
<img src=”/”image1.jpg”” width=100 name=”myImage1″ border=0>
</a>
41 创建幻灯片

<script language=”JavaScript”>
var imageList = new Array;
imageList[0] = new Image;
imageList[0].src = “image1.jpg”;
imageList[1] = new Image;
imageList[1].src = “image2.jpg”;
imageList[2] = new Image;
imageList[2].src = “image3.jpg”;
imageList[3] = new Image;
imageList[3].src = “image4.jpg”;
function slideShow(imageNumber) {
document.slideShow.src = imageList[imageNumber].src;
imageNumber += 1;
if (imageNumber < imageList.length) {
window.setTimeout(“slideShow(” + imageNumber + “)”,3000);
}
}
</script>
</head>
20: <body onLoad=”slideShow(0)”>
2<img src=”/”image1.jpg”” width=100 name=”slideShow”>
42 随机广告图片

<script language=”JavaScript”>
var imageList = new Array;
imageList[0] = “image1.jpg”;
imageList[1] = “image2.jpg”;
imageList[2] = “image3.jpg”;
imageList[3] = “image4.jpg”;
var urlList = new Array;
urlList[0] = “http://skyonsea.com/“;
urlList[1] = “http://another.host/”;
urlList[2] = “http://somewhere.else/”;
urlList[3] = “http://right.here/”;
var imageChoice = Math.floor(Math.random() * imageList.length);
document.write(‘<a href=”’ + urlList[imageChoice] + ‘”><img src=”’ + imageList[imageChoice] + ‘”></a>’);
</script>
avaScript就这么回事4：表单

43 表单构成

<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

<form name=”myForm”>
<input type=”text” name=”myText”>
</form>
<a href=’#’ onClick=’window.alert(document.myForm.myText.value);’>Check Text Field</a>
45 动态复制文本框内容

<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>
46 侦测文本框的变化

<form name=”myForm”>
Enter some Text: <input type=”text” name=”myText” onChange=”alert(this.value);”>
</form>
47 访问选中的Select

<form name=”myForm”>
<select name=”mySelect”>
<option value=”First Choice”>1</option>
<option value=”Second Choice”>2</option>
<option value=”Third Choice”>3</option>
</select>
</form>
<a href=’#’ onClick=’alert(document.myForm.mySelect.value);’>Check Selection List</a>
48 动态增加Select项

<form name=”myForm”>
<select name=”mySelect”>
<option value=”First Choice”>1</option>
<option value=”Second Choice”>2</option>
</select>
</form>
<script language=”JavaScript”>
document.myForm.mySelect.length++;
document.myForm.mySelect.options[document.myForm.mySelect.length – 1].text = “3″;
document.myForm.mySelect.options[document.myForm.mySelect.length – 1].value = “Third Choice”;
</script>
49 验证表单字段

<script language=”JavaScript”>
function checkField(field) {
if (field.value == “”) {
window.alert(“You must enter a value in the field”);
field.focus();
}
}
</script>
<form name=”myForm” action=”target.html”>
Text Field: <input type=”text” name=”myField”onBlur=”checkField(this)”>
<br><input type=”submit”>
</form>
50 验证Select项

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

<form name=”myForm” action=”login.html”>
Username: <input type=”text” name=”username”><br>
Password: <input type=”password” name=”password”><br>
<input type=”button” value=”Login” onClick=”this.form.submit();”>
<input type=”button” value=”Register” onClick=”this.form.action = ‘register.html’; this.form.submit();”>
<input type=”button” value=”Retrieve Password” onClick=”this.form.action = ‘password.html’; this.form.submit();”>
</form>
52 使用图像按钮

<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

<SCRIPT LANGUAGE=’JavaScript’>
<!–
function encrypt(item) {
var newItem = ”;
for (i=0; i < item.length; i++) {
newItem += item.charCodeAt(i) + ‘.’;
}
return newItem;
}
function encryptForm(myForm) {
for (i=0; i < myForm.elements.length; i++) {
myForm.elements.value = encrypt(myForm.elements.value);
}
}
//–>
</SCRIPT>
<form name=’myForm’ onSubmit=’encryptForm(this); window.alert(this.myField.value);’>
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

<script language=”JavaScript”>
window.status = “A new status message”;
</script>
55 弹出确认提示框

<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

<script language=”JavaScript”>
var userName = window.prompt(“Please Enter Your Name”,”Enter Your Name Here”);
document.write(“Your Name is ” + userName);
</script>
57 打开一个新窗口

//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

<script language=”JavaScript”>
window.open(“http://www.liu21st.com/”,”myNewWindow”,’height=300,width=300′);
</script>
59 设置新窗口的位置

<script language=”JavaScript”>
window.open(“http://www.liu21st.com/”,”myNewWindow”,’height=300,width=300,left=200,screenX=200,top=100,screenY=100′);
</script>
60 是否显示工具栏和滚动栏

<script language=”JavaScript”>
window.open(“http:
61 是否可以缩放新窗口的大小

<script language=”JavaScript”>
window.open(‘http://www.liu21st.com/’ , ‘myNewWindow’, ‘resizable=yes’ );</script>
62 加载一个新的文档到当前窗口

<a href=’#’ onClick=’document.location = ’125a.html’;’ >Open New Document</a>
63 设置页面的滚动位置

<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

<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

<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

<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

<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文件中有个脚本

function doAlert() {
window.alert(“Frame 1 is loaded”);
}

那么在frame2中可以如此调用该方法

<body onLoad=”parent.frame1.doAlert();”>
This is frame 2.
</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

<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

<frameset cols=”0,50%,*”>
<frame name=”codeFrame” src=”/”140code.html””>
<frame name=”frame1″ src=”/”140a.html””>
<frame name=”frame2″ src=”/”140b.html””>
</frameset>