【javascript每日一练】- 利用闭包

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>闭包</title>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
$(function(){
	$('#test li').click(function(){
		var index=$('#test li').index($(this));
		alert(index);	
	})
})
</script>
</head>

<body>
<ul id='test'>
    <li>这是第一条</li>
    <li>这是第二条</li>
    <li>这是第三条</li>
</ul>
</body>
</html>

 利用闭包,代码简洁但增加了内存消耗

	var ele=$('#test');
	var liNode=ele.find('li');
	var len=liNode.length;
	for(var i=0;i<=len-1;i++){
		liNode[i].onclick=(function(x){
			return function(){
				console.log(x);
				//return x;
			}
		})(i)
	}

 增加自定义属性,改变了html代码

    var ele=$('#test');
	var liNode=ele.find('li');
	var len=ele.find('li').length;
	for(var i=0;i<=len-1;i++){
		ele.find('li').eq(i).attr('index',i);
		ele.find('li').eq(i).click(function(){
			alert($(this).attr('index'));
		})
	}

转载于:https://www.cnblogs.com/positive/p/3596599.html

猜你喜欢

转载自blog.csdn.net/weixin_33915554/article/details/93495721