js实现验证码的操作

登录很多应用时都需要验证码，今天我用js实现了一个简单的随机验证码，在适当时刻调用接口就行。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">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .wrap {
            position: absolute;
            top: 0;
            right: 0;
            left: 0;
            bottom: 0;
            margin: auto;
            width: 300px;
            height: 200px;
            box-shadow: 0 0 8px #999;
            border-radius: 10px;
        }
        
        .wrap .wrap-title {
            text-align: center;
            line-height: 30px;
            font-family: Arial, Helvetica, sans-serif;
            font-weight: bold;
            font-size: 12px;
        }
        
        .wrap .wrap-show {
            height: 140px;
            text-align: center;
            line-height: 140px;
        }
    </style>
</head>

<body>
    <div class="wrap">
        <div class="wrap-title">获取验证码</div>
        <!-- 验证码存放处 -->
        <div class="wrap-show"></div>
        <button>点击获取验证码</button>
    </div>

    <script>
        function myFerCode() {
            // 定义字符串，用来存放待命字符
            var staChar = "ABCDEFGHIGKLMNOPQRSTUVWXYZabcdefghigklmnopqrstuvwxyz0123456789";
            var str = ""; // 定义变量，存放随机截取拼接后的字符串
            // 遍历操作，随机提取字符串
            for (var i = 0; i < 6; i++) { // i<4此处的4任意修改，想拿到几位数的验证码就将此处修改为几
                str += (staChar[parseInt(Math.random() * staChar.length)]);
            }
            return str;
        }
        var oBtn = document.querySelector("button"),
            oShow = document.querySelector(".wrap-show");

        oBtn.onclick = function() {
            oShow.innerHTML = myFerCode();
        }
    </script>
</body>

</html>

原文地址：https://www.cnblogs.com/zhzq1111/p/11751999.html