如何检测页面是否有重复的id属性值

<!DOCTYPE html> 
<html> 
<head> 
<meta charset=" utf-8"> 
<meta name="author" content="http://www.51texiao.cn/" />
<title>蚂蚁部落</title>
<script type="text/javascript">
window.onload=function(){
var tags=document.getElementsByTagName("*"),
count=tags.length, time, ret = {}, id;
time=new Date();
for(var i = 0; i < count; i++)
{
   id=tags[i].id;
   if(id)
   {
     if(ret[id])
     {
       alert(id + "/n用时:" + (new Date() - time));
       return;
     }
     else
     {
       ret[id]=true;
     }
   }
}
alert("未找到相同ID");
}
</script>
</head>
<body>
</body>
</html>
原文地址:https://www.cnblogs.com/makan/p/4682114.html