电灯开关案例 

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>电灯开关</title>
 6 </head>
 7 <body>
 8 <img id="light" src="img/off.gif">
 9 <script>
10 
11     //1.获取图片对象
12     var light=document.getElementById("light");
13     var flag=false;
14     //2.绑定单击事件
15     light.onclick=function () {
16          if(flag){
17              light.src="img/off.gif";
18              flag=false;
19          }else {
20              light.src="img/on.gif";
21              flag=true;
22          }
23     }
24 </script>
25 </body>
26 </html>

 

 

 

posted @ 2021-06-02 19:06  丁帅帅dss  阅读(41)  评论(0)    收藏  举报