JavaScript中可以对内建对象进行扩展。
<html>
<head><title>Test of heading method</title>
</head>
<body>
<script LANGUAGE="JavaScript" type="text/javascript">
function addhead (level) {
html = "H" + level;
text = this.toString();
start = "<" + html + ">";
stop = "</" + html + ">";
return start + text + stop;
}
String.prototype.heading = addhead;
document.write ("This is a heading 1".heading(1));
document.write ("This is a heading 2".heading(2));
document.write ("This is a heading 3".heading(3));
</script>
</body>
</html>
1，Prototype
Prototype is free, open-source software. You can download it from its official website at http://prototype.conio.net/. Prototype is also built into the Ruby on Rails framework for the server-side language Rubysee http://www.rubyonrails.com/ for more information.
2，Script.aculo.us
Script.aculo.us by Thomas Fuchs is one such library. It includes functions to simplify drag-and-drop tasks, such as rearranging lists of items. It also includes a number of Combination Effects, which enable you to use highlighting and animated transitions within your pages.
3，AJAX Frameworks
The Prototype library, described previously, includes AJAX features. There are also many dedicated AJAX libraries. One of the most popular is SAJAX (Simple AJAX), an open-source toolkit that makes it easy to use AJAX to communicate with PHP, Perl, and other languages from JavaScript. Visit the SAJAX website for details at http://www.modernmethod.com/sajax.
4，Dojo (http://www.dojotoolkit.org/) is an open-source toolkit that adds power to JavaScript to simplify building applications and user interfaces. It adds features ranging from extra string and math functions to animation and AJAX.
5， The Yahoo! UI Library (http://developer.yahoo.net/yui/) was developed by Yahoo! and made available to everyone under an open-source license. It includes features for animation, DOM features, event management, and easy-to-use user interface elements such as calendars and sliders.
6， MochiKit (http://mochikit.com/) is a lightweight library that adds features for working with the DOM, CSS colors, string formatting, and AJAX. It also supports a nice logging mechanism for debugging your scripts.
本文转自Phinecos(洞庭散人)博客园博客，原文链接：http://www.cnblogs.com/phinecos/archive/2007/05/12/744215.html，如需转载请自行联系原作者
