JavaScript点击按钮生成4位随机验证码

本文实例为大家分享了js实现点击按钮生成4位随机验证码的具体代码，供大家参考，具体内容如下

效果图：

代码：

!DOCTYPE htML>
    html lang="en">
     head>
     meta charset="UTF-8">
     meta name="viewport" content="width=device-width, inITial-scale=1.0">
     title>
    Document/title>
     style>
 div {
      width: 100px;
      height: 50px;
      background: red;
      text-align: center;
      line-height: 50px;
 }
     /style>
    /head>
     body>
     div id="yzm">
    /div>
     button id="BTn">
    点击生成验证码/button>
     script>
     // VAR str = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
     //数组转换为字符串 // var arr = str.split("");
      var arr = ["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", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"];
     // console.LOG(arr);
     //页面刚加载时候调用它 sjs(arr);
  btn.onclick = function() {
      sjs(arr);
 }
  function sjs(arr) {
      var code = Math.floor(Math.random() * arr.length);
      var code1 = Math.floor(Math.random() * arr.length);
      var code2 = Math.floor(Math.random() * arr.length);
      var code3 = Math.floor(Math.random() * arr.length);
      var n = arr[code] + arr[code1] + arr[code2] + arr[code3];
  yzm.innerHTML = n }
     /script>
    /body>
     /html>
    

小编再为大家分享一段代码：点击产生四位随机数字母与数字

!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>
    点击产生随机数/title>
      style>
  span{
        display: block;
        width: 110px;
        height: 50px;
        border: 1px solid red;
        text-align: center;
        line-height: 50px;
  }
      /style>
    /head>
    body>
      span id="demo" onclick="init();
    ">
    /span>
      script>
        init();
    function init(){
        var arr=[];
        for(var i=48;
    i123;
i++){
         if(i>
    57 &
    &
     i65) continue;
         if(i>
    90 &
    &
     i97) continue;
         arr.push(String.FromCharCode(i));
    }
    arr.sort(function () {
         return Math.random()-0.5;
    }
    );
        arr.length=4;
            var span= document.getElementById('demo');
        span.textContent=(arr.join(""));
        }
        /script>
    /body>
    /html>
    

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。

• JS实现随机生成验证码
• JavaScript实现随机生成验证码及校验
• JavaScript实现4位随机验证码的生成
• JavaScript函数封装随机颜色验证码(完整代码)

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