闭包实现(鼠标滑过)当前行高亮显示 

 1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
 2 <html>
 3 <head>
 4     <title>新建网页</title>
 5     <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
 6     <meta name="description" content=""/>
 7     <meta name="keywords" content=""/>
 8 
 9     <script type="text/javascript">
10         window.onload=function(){
11             var lis = document.getElementsByTagName('li');
12             for(var i=0; i<lis.length; i++){
13 /*                lis[i].onmouseover = function(){
14                     lis[i].style.backgroundColor = "lightblue";     //这里面i是四
15                 }*/
16 
17                 //over()获得闭包函数，工调用了4次，这样系统要生成4个函数
18                 //函数内部的n分别为：0，1，2，3
19                 lis[i].onmouseover = over(i);
20                 lis[i].onmouseout = out(i);
21             }
22             function over(n){
23                 function fs(){
24                     lis[n].style.backgroundColor = "lightblue";
25                 }
26                 return fs;
27             }
28             function out(n){
29                 function fs(){
30                     lis[n].style.backgroundColor = "";
31                 }
32                 return fs;
33             }
34 
35         }
36     </script>
37 </head>
38 <body>
39 <ul>
40     <li>刘备</li>
41     <li>曹操</li>
42     <li>孙权</li>
43     <li>董卓</li>
44 </ul>
45 </body>
46 </html>

 

posted @ 2014-11-17 21:24  敲着键盘看风景  阅读(179)  评论(0)    收藏  举报