JS的className，字体放大缩小

 1 <!DOCTYPE HTML>
 2 <html>
 3 <head>
 4 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
 5 <title>无标题文档</title>
 6 <script>
 7 window.onload = function (){
 8     var oBtn1 = document.getElementById('btn1');
 9     var oBtn2 = document.getElementById('btn2');
10     var oBtn3 = document.getElementById('btn3');
11     var oBtn4 = document.getElementById('btn4');
12     var oP = document.getElementById('p1');
13     var num = 14;
14     
15     oBtn1.onclick = function (){
16         num -= 2;
17         oP.style.fontSize = num + 'px';
18         // JS 不允许出现"-"
19         // padding-top        paddingTop
20         // margin-left        marginLeft
21     };
22     oBtn2.onclick = function (){
23         // num = num + 2;
24         num += 2;
25         
26         oP.style.fontSize = num + 'px';
27         // JS 不允许出现"-"
28     };
29     
30     oBtn3.onclick = function (){
31         // oP.class = 'red';
32         // class => className
33         oP.className = 'red';
34     };
35     oBtn4.onclick = function (){
36         // oP.class = 'red';
37         // class => className
38         oP.className = 'yellow';
39     };
40 };
41 </script>
42 <style>
43 .red { width:400px; border:10px solid #333; background:red; padding:20px; color:yellow; }
44 .yellow { width:500px; border:5px solid #333; background:yellow; padding:10px; color:red; }
45 </style>
46 </head>
47 
48 <body>
49 
50 <input id="btn1" type="button" value="-" />
51 <input id="btn2" type="button" value="+" />
52 <input id="btn3" type="button" value="红" />
53 <input id="btn4" type="button" value="黄" />
54 <p id="p1" style="font-size:16px;">10月28日晚，中央纪委监察部官网发布消息，贵州省委常委、遵义市委书记廖少华因涉嫌严重违纪违法接受组织调查。3天后中组部宣布对其免职。廖成为十八大后中纪委一连串"打虎"行动中第十一位落马的副省部级以上高官。</p>
55 
56 </body>
57 </html>
posted on 2016-03-07 14:40 hduhdc 阅读(467) 评论(0) 收藏举报