jquery中选择器含有空格的情况
后代选择器和过滤选择器不同
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
2 <html xmlns="http://www.w3.org/1999/xhtml">
3 <head>
4 <title> new document </title>
5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
6 <!-- 引入jQuery -->
7 <script src="http://www.cnblogs.com/scripts/jquery-1.3.1.js" type="text/javascript"></script>
8 <script type="text/javascript">
9 $(function(){
10 //注意区分类似这样的选择器
11 //虽然一个空格，却截然不同的效果.
12 var $t_a = $('.test :hidden'); //后代选择器
13 var $t_b = $('.test:hidden'); //过滤选择器
14 var len_a = $t_a.length;
15 var len_b = $t_b.length;
16 alert("$('.test :hidden') = " + len_a); //输出 4
17 alert("$('.test:hidden') = " + len_b); //输出 3
18 })
19 </script>
20 </head>
21 <body>
22 <div class="test">
23 <div >aa</div>
24 <div >bb</div>
25 <div >cc</div>
26 <div class="test" >dd</div>
27 </div>
28 <div class="test" >ee</div>
29 <div class="test" >ff</div>
30 </body>
31 </html>