js生成验证码并验证
<html><head><title>验证码</title><style type="text/css">.code{font-family:Arial;font-style:italic;font-weight:bold;border:0;letter-spacing:3px;color:blue;}</style><script type = "text/javascript" src = "checkCode.js"></script></head><body><div><input type = "text" id = "input"/><input type = "button" id="checkCode" class= "code" onclick="createCode()"/><a href = "#" onclick = "createCode()">看不清楚</a><br><input type = "button" value = "验证" onclick = "validate()"/></div></body></html>
checkCode.js
var code ; //在全局定义验证码 //产生验证码window.onload = function createCode(){ code = ""; var codeLength = 4;//验证码的长度 var checkCode = document.getElementById("checkCode"); var random = new Array(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');//随机数 for(var i = 0; i < codeLength; i++) {//循环操作var charIndex = Math.floor(Math.random()*36);//取得随机数的索引code += random[charIndex];//根据索引取得随机数加到code上}checkCode.value = code;//把code值赋给验证码}//校验验证码function validate(){var inputCode = document.getElementById("input").value.toUpperCase(); //取得输入的验证码并转化为大写 if(inputCode.length <= 0) { //若输入的验证码长度为0alert("请输入验证码！"); //则弹出请输入验证码} else if(inputCode != code ) { //若输入的验证码与产生的验证码不一致时alert("验证码输入错误！"); //则弹出验证码输入错误createCode();//刷新验证码} else { //输入正确时alert("^-^"); //弹出^-^} }