getByClassName2016/4/21

<!DOCTYPE HTML>
<html>
	<head>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
	<title>ll无标题文档</title>
	<script>
window.onload=function(){
     
	 var ali=getElementByClassName(document,'li','box');
	 for(var i=0;i<ali.length;i++)
	 {
		ali[i].style.background='red';
	 }
	alert(ali.length);
	 function getElementByClassName(parent,tagName,className){
			 var aEls=parent.getElementsByTagName(tagName);
			 var arr=[]; 
			 for(var i=0;i<aEls.length;i++)
			 {
				var aclassName=aEls[i].className.split(' ');
					for(var j=0;j<aclassName.length;j++)
					{
						if(aclassName[j]==className){
						arr.push(aEls[i]);
						break;
							}
				
					}
			 
	 
			 
			}
			 return arr;


	}
};
 
</script>
	
	
	
	</head>

<body>
	<ul id="ul1">
		<li>111111</li>
		<li>22222</li>
		<li class="box ">33333</li>
		<li class="box ">444444</li>
	</ul>
	   
</body>
</html>

  

原文地址:https://www.cnblogs.com/hduhdc/p/5417317.html