<!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>jQuery</title>
<script?type="text/javascript"?src="js/jquery.min.js"></script>
<script?type="text/javascript">
$(document).ready(function()?{
var?n?=?$(".dv1").index($("#dv2"));
alert(n);
});
</script>
<style>
</style>
</head>
<body>
<div>aaa</div>
<div>bbb</div>
<div?class="dv1">cccM</div>
<div?class="dv1"?id="dv2">ddd</div>
<div>sss</div>
<div?class="dv">vvv</div>
</body>
</html>
為什么id="dv2"的div 去掉了 class="dv1"，index()返回值為-1呢？
慕粉1913103917
2017-05-02 14:32:45
