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发表于 2017-9-9 19:49:35
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本帖最后由 不二如是 于 2017-9-9 19:54 编辑
id唯一,所以需要指定两回。
- <!DOCTYPE html>
- <html>
- <head>
- <meta charset="UTF-8">
- <link rel="stylesheet" type="text/css" href="css/style.css">
- <title>Insert title here</title>
- <script type="text/javascript">
- function numb(){
- var num1 = parseInt(Math.round((Math.random())*20));
- document.getElementById('num1').innerHTML = num1;
- var num2 = parseInt(Math.round((Math.random())*20));
- document.getElementById('num2').innerHTML = num2;
- }
- </script>
- </head>
- <body onload="numb()">
- <div>
- <span id="num1"></span> + <span id="num2"></span> = <br>
- </div>
- </body>
- </html>
复制代码
class不唯一,注意语法:
- <!DOCTYPE html>
- <html>
- <head>
- <meta charset="UTF-8">
- <link rel="stylesheet" type="text/css" href="css/style.css">
- <title>Insert title here</title>
- <script type="text/javascript">
- function numb(){
- var num1 = parseInt(Math.round((Math.random())*20));
- document.getElementsByClassName("num1")[0].innerHTML = num1;
- document.getElementsByClassName("num1")[1].innerHTML = num1;
- }
- </script>
- </head>
- <body onload="numb()">
- <div>
- <span class="num1"></span> + <span class="num1"></span> = <br>
- </div>
- </body>
- </html>
复制代码
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