JavaScript验证码

article/2025/11/6 1:24:08

验证码在生活中很常见，所以做了个验证码案例：
在这里插入图片描述
感觉蛮简单的，就不解释了，代码里有注释，如下：

		var span =  document.getElementsByTagName('span')[0];var a = document.getElementsByTagName('a')[0];var input = document.getElementsByTagName('input')[0];var btn = document.getElementsByTagName('button')[0];var code = "";//生成验证码function createCode(){code="";var codelength = 6; //设置验证码位数；//设置验证码生成数组，验证码从中取直；var codeArr = 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','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');//随机获取验证码数组下标，生成验证码for(var i=0; i<codelength; i++){code += codeArr[Math.floor(Math.random()*codeArr.length)];}span.innerText = code;return code;}//cresteCode();window.onload = function(){createCode();}a.onclick = function(){createCode();return false;}btn.onclick = function(){if(input.value == ""){alert("验证码为空，请输入验证码！");}else if(input.value.toLocaleUpperCase() == code.toLocaleUpperCase()){alert("验证码输入正确！");}else {alert("验证码输入错误，请重新输入验证码！");createCode();}}

html：

	<div id="wrap"><div id="code"><span></span><a href="">看不清楚换一个</a></div><div id="checkcode"><ul><li>请输入验证码：<input type="text"></li><li><button>验证</button></li></div></div>