js 随机验证码生成及校验 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>随机验证码校验</title>
    <style type="text/css">
        #code{
            width: 100px;
            height: 100px;
            background: #ddd;
            padding: 10px;
            line-height: 100px;
            text-align: center;
            font-size: 20px;
            color: red;
            font-weight: bold;
        }
        input{
            outline: none
        }
    </style>
</head>
<body>
    <div id="code"></div>
    <input type="text" id="newCode">
    <input type="button" id="validate" value="验证">
    <script type="text/javascript">
    window.onload = function(){
        var code 
        var codeDiv =document.getElementById('code')
        var newCode = document.getElementById('newCode')
        var validate = document.getElementById('validate')
        creatCode()
        
        function creatCode(){//随机生成验证码
            code = ""
            var codeLength = 4
            var randomCode = [
                0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','I','G','K','L','M',
                'N','O','P','Q','R','S','T','U','V','W','X','Y','Z'
            ]
            for(var i=0; i<codeLength; i++){
                var index = Math.floor(Math.random() * 36);
                code += randomCode[index]
            }
            codeDiv.innerHTML = code
        }
        
        validate.onclick = function(){// 验证验证码
            var inputCode = newCode.value.toUpperCase()
            if(inputCode==code){//验证通过
                alert("验证通过")
            }else{//验证码不正确
                alert("验证码不正确")
                newCode.value = ''
                creatCode()
            }
        }
    }
    </script>
</body>
</html>

效果

posted @ 2021-04-06 11:54  张先生zy  阅读(251)  评论(0)  编辑  收藏  举报