JavaScript实现随机标签云效果代码

<!DOCTYPE HTML>
<html>
<head>
<meta charset="UTF-8">
<title>随机标签云</title>
<style type="text/css">
*{
  margin:0;
  padding:0
}
a{ 
  text-decoration:none
}
#wrap{
  width:400px;
  margin:auto
}
</style>
 <script type="text/javascript">
  window.onload=function(){
   var obox=document.getElementById("wrap");
   var obj=obox.getElementsByTagName("a");
   //随机方法
   function rand(num){
    return parseInt(Math.random()*num+1);
   }
   //随机颜色值
   function randomcolor(){
    var str=Math.ceil(Math.random()*16777215).toString(16);
    if(str.length<6){
     str="0"+str;
    }
    return str;
   }
   //循环
   for( len=obj.length,i=len;i--;){
    obj[i].className="color"+rand(5);
    obj[i].style.zIndex=rand(5);
    obj[i].style.fontSize=rand(12)+12+"px";
    // obj[i].style.background="#"+randomcolor();
    obj[i].style.color="#"+randomcolor();
    obj[i].onmouseover=function(){
     this.style.background="#"+randomcolor();
    }
    obj[i].onmouseout=function(){
     this.style.background="none";
    }
   }
  }
 </script>
</head>
<body>
 <div id="wrap">
  <a href="#">web标准学习</a>
  <a href="#">css</a>
  <a href="#">javascript</a>
  <a href="#">html5</a>
  <a href="#">canvas</a>
  <a href="#">video</a>
  <a href="#">audio</a>
  <a href="#">jQuery</a>
  <a href="#">jQuerymobile</a>
  <a href="#">flash</a>
  <a href="#">firefox</a>
  <a href="#">chrome</a>
  <a href="#">opera</a>
  <a href="#">IE9</a>
  <a href="#">css3.0</a>
  <a href="#">andriod</a>
  <a href="#">apple</a>
  <a href="#">google</a>
  <a href="#">jobs</a>
 </div>
</body>
</html>