废话不多说，咱们直接上效果图和案例实现代码：
效果图如下所示：
具体实现代码如下：
<!DOCTYPE html> <html lang=”en”>
<head> <meta charset=”UTF-8″> <meta name=”viewport” content=”width=device-width, initial-scale=1.0″> <title>Document</title> </head> <style> input[type=‘button‘]{ margin-left: 100px; } input{ margin-top: 200px; } </style> <body> <input type=”button” id=”btn” value=”点击生成随机数”> <input type=”text” disabled id=‘txt‘>
<script> var btn = document.getElementById(‘btn‘); var txt = document.getElementById(‘txt‘); btn.onclick = function () { txt.value = fn(); } function fn() { var rs = ‘‘; var sjs = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ‘a‘, ‘b‘, ‘c‘, ‘d‘, ‘e‘, ‘f‘, ‘g‘, ‘h‘, ‘i‘, ‘j‘, ‘k‘, ‘l‘, ‘m‘, ‘n‘, ‘o‘, ‘p‘, ‘q‘,‘r‘,‘s‘,‘t‘,‘u‘,‘v‘,‘w‘,‘x‘,‘y‘,‘z‘];
//如果像生成多位数验证码，只需改变下面的4为你需要的位数值即可 for (var i = 0; i < 4; i++) { var n = Math.floor(Math.random() * sjs.length); var n = sjs[n]; rs = rs + n; } return rs; } txt.value = fn(); </script> </body>
</html>