1. 效果图
2. 源码
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<style>
li { height:24px; margin-bottom:3px; list-style:none; }
</style>
</head>
<body>
<ul id="ul1">
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
<script>
window.onload = function(){
var aLi = document.getElementsByTagName(‘li‘)
var arrColor = [‘red‘,‘yellow‘,‘blue‘]
for(var i=0; i < aLi.length; i++){
aLi[i].index = i;
aLi[i].style.background = arrColor[i % arrColor.length]
aLi[i].onmouseover = function(){
this.style.background = ‘gray‘;
}
aLi[i].onmouseout = function(){
this.style.background = arrColor[this.index % arrColor.length]
}
}
}
</script>
</body>
</html>
原文：http://www.cnblogs.com/bravolove/p/5982718.html