正文
classname 就是在css上添加类，然后js的类名等于
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| <!DOCTYPE HTML> | |
| <html> | |
| <head> | |
| <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> | |
| <title>无标题文档</title> | |
| <script> | |
| window.onload = function (){ | |
| var oBtn1 = document.getElementById('btn1'); | |
| var oBtn2 = document.getElementById('btn2'); | |
| var oBtn3 = document.getElementById('btn3'); | |
| var oBtn4 = document.getElementById('btn4'); | |
| var oP = document.getElementById('p1'); | |
| var num = 14; | |
| oBtn1.onclick = function (){ | |
| num -= 2; | |
| oP.style.fontSize = num + 'px'; | |
| // JS 不允许出现"-" | |
| // padding-top paddingTop | |
| // margin-left marginLeft | |
| }; | |
| oBtn2.onclick = function (){ | |
| // num = num + 2; | |
| num += 2; | |
| oP.style.fontSize = num + 'px'; | |
| // JS 不允许出现"-" | |
| }; | |
| oBtn3.onclick = function (){ | |
| // oP.class = 'red'; | |
| // class => className | |
| oP.className = 'red'; | |
| }; | |
| oBtn4.onclick = function (){ | |
| // oP.class = 'red'; | |
| // class => className | |
| oP.className = 'yellow'; | |
| }; | |
| }; | |
| </script> | |
| <style> | |
| .red { width:400px; border:10px solid #333; background:red; padding:20px; color:yellow; } | |
| .yellow { width:500px; border:5px solid #333; background:yellow; padding:10px; color:red; } | |
| </style> | |
| </head> | |
| <body> | |
| <input id="btn1" type="button" value="-" /> | |
| <input id="btn2" type="button" value="+" /> | |
| <input id="btn3" type="button" value="红" /> | |
| <input id="btn4" type="button" value="黄" /> | |
| <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> | |
| </body> | |
| </html> | |
