【 tulaoshi.com - Web开发 】
                             
                             代码如下:
!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd" 
html 
head 
meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" 
titleEach Document/title 
script type="text/javascript" 
(function(){ //创建一个自执行函数 
function _$(el){ //声明一个类 
this.elements = []; //用于保存DOM元素的引用 
for (var i = 0; i  el.length; i++) { 
var element = el[i]; 
if (typeof element == string ) { 
element = document.getElementById(element); 
} 
this.elements.push(element); 
} 
} 
_$.prototype = { 
each: function(fn){ 
for (var i = 0; i  this.elements.length; i++) { 
fn.call(this, this.elements[i]); //第二个参数是fn函数的参数 
} 
}, 
setStyle: function(prop, val){ 
var that = this; 
this.each(function(el){ //注意参数的设置 
el.style[prop] = val; 
}); 
return this; 
} 
} 
window.$ = function(){ 
return new _$(arguments); 
}; 
})(); 
window.onload = function(){ 
$("p", "p2").setStyle("color", "red"); 
} 
/script 
/head 
body 
p id="p" 
Hello world 
/p 
p id="p2" 
Welcome. 
/p 
/body 
/html