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Use JavaScript to create random verification codes for web pages

一个新手
一个新手Original
2017-09-26 10:06:362243browse

1: getCode.js

/** * 产生随机数的函数 */function validateCode(n){    //验证码可能包含的字符    
var s="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";    
var ret=""; //用于保存生成的验证码    //利用循环,随机产生生成验证码的每一个字符    
for(var i=0;i<n;i++) {        
var index = Math.floor(Math.random() * 62); //随机产生一个0~62之间的数字        
ret += s.charAt(index);//将随机产生的数字当作字符串的位置下标,在字符串s中取出该字符，并加入到ret中    }        
return ret; //返回产生的验证码}/* 显示随机数的函数 */function show() {    
document.getElementById("msg").innerHTML=validateCode(4);//在id为msg的对象显示验证码}window.onload=show();//在整个页面加载完成后执行此函数

2:checkCode.html  

<!DOCTYPE html><html lang="en"><head>
    <meta charset="UTF-8">
    <title>制作网页随机验证码</title>
    <script type="text/javascript" src="getCode.js"></script></head><body>
    <span id="msg"></span>
    <input type="button" value="刷新" onclick="show()"></body></html>

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