JQuery学习(层级)ancestor & descendant

 1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
 2 <%
 3     String path = request.getContextPath();
 4     String basePath = request.getScheme() + "://"
 5             + request.getServerName() + ":" + request.getServerPort()
 6             + path + "/";
 7 %>
 8 
 9 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
10 <html>
11 <head>
12 <base href="<%=basePath%>">
13 
14 <title>My JSP 'jquery.jsp' starting page</title>
15 
16 <meta http-equiv="pragma" content="no-cache">
17 <meta http-equiv="cache-control" content="no-cache">
18 <meta http-equiv="expires" content="0">
19 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
20 <meta http-equiv="description" content="This is my page">
21 <script type="text/javascript" src="/common/easyui/jquery.min.js"></script>
22 <script type="text/javascript">
23     $(document).ready(function(){
24     $("form input").css("background-color","yellow");
25     });
26     
27 </script>
28 
29 </head>
30 <body>
31 <form>
32   <label>Name:</label>
33   <input name="name" />
34   <fieldset>
35       <label>Newsletter:</label>
36       <input name="newsletter" />
37  </fieldset>
38 </form>
39 <input name="none" /> 
40 
41 </body>
42 </html>

　　　　　　　　　　　　效果图1-1

重点解释：

 $("form input")：即form下所有input
结合JQuery1.4.2API还有：

parent>children:父元素下所有子元素
$("form > input")：form下所有input

prev+next:跟在prev后所有的next元素
$("form+input"):跟在form后的所有input元素

prev ~ siblings:与prev同级的siblings元素
$("form ~ input"):与form同级的input元素