1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
2 <html>
3 <head>
4 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
5 <title>第3章示例5</title>
6 <style type="text/css">
7 body { width:780px; }
8 div,p,h3,span { border:4px solid black; background-color:green; color:white; float:left; margin:6px; padding:5px; font:bold 14px/1 Arial,Helvetica,sans-serif; width:220px; display:block; }
9 div p,div span { width:205px; border-width:2px; margin:5px 0; float:none; }
10 p span { width:193px; border-width:1px;}
11 h3 { margin-right:500px; }
12 .clear { clear:both; }
13 .relative { position:relative; }
14 .highlight { background-color:gold; color:black; }
15 form { clear:both; font:bold 14px/1 Arial,Helvetica,sans-serif; }
16 button { font:bold 16px/1 Arial,Helvetica,sans-serif; margin:1px 3px; padding:2px; cursor:pointer; }
17 </style>
18 <script src="http://code.jquery.com/jquery-1.9.1.min.js" type="text/javascript"></script>
19 <script type="text/javascript">
20 $(document).ready(function(){
21 $("button").click(function(){$("*").removeClass("highlight");});
22 $("#btn1").click(function(){$("div").add("p:last").addClass("highlight");});
23 $("#btn2").click(function(){$("body").children(":eq(3)").prevAll("[class]").andSelf().addClass("highlight");});
24 $("#btn3").click(function(){$("body").children(":eq(3)").prevAll("[class]").andSelf().andSelf().addClass("highlight");});
25 $("#btn4").click(function(){$("body").children(":eq(3)").prevAll("[class]").andSelf().children("p").andSelf().addClass("highlight");});
26 });
27 </script>
28 </head>
29 <body>
30 <div class="clear">
31 <div class="clear">
32 <p>
33 <p>
34 <span><span> </span></span>
35 </p>
36 </p>
37 </div>
38 </div>
39 <div>
40 <div>
41 <p><p> </p></p>
42 <p><p> </p></p>
43 <p><p> </p></p>
44 </div>
45 </div>
46 <div class="relative">
47 <div class="relative">
48 <span><span> </span></span>
49 <span><span> </span></span>
50 <span class="clear"><span class="clear"> </span></span>
51 </div>
52 </div>
53 <h3 class="clear"><h3 class="clear"> </h3></h3>
54 <div class="clear">
55 <div class="clear">
56 <p>
57 <p>
58 <span><span> </span></span>
59 <span><span> </span></span>
60 </p>
61 </p>
62 <p>
63 <p>
64 <span><span> </span></span>
65 <span><span> </span></span>
66 </p>
67 </p>
68 </div>
69 </div>
70 <div>
71 <div>
72 <p><p> </p></p>
73 <p><p> </p></p>
74 <p><p> </p></p>
75 </div>
76 </div>
77 <div class="relative">
78 <div class="relative">
79 <span><span> </span></span>
80 <span><span> </span></span>
81 <span class="clear"><span class="clear"> </span></span>
82 </div>
83 </div>
84 <form>
85 <button type="button" id="btn1">$("div").add("p:last")</button>
86 <button type="button" id="btn2">$("body").children(":eq(3)").prevAll("[class]").andSelf()</button>
87 <button type="button" id="btn3">$("body").children(":eq(3)").prevAll("[class]").andSelf().andSelf()</button>
88 <button type="button" id="btn4">$("body").children(":eq(3)").prevAll("[class]").andSelf().children("p").andSelf()</button>
89 </form>
90 </body>
91 </html>
![](//images0.cnblogs.com/blog/364021/201303/05193135-d4838c4dd35d495fa9941bc78b463539.jpg)