js随机验证码 | 随机验证码

随机验证码：
<!DOCTYPE html>

<html>

    <head>

        <meta charset="UTF-8">

        <title></title>

        <style>

            *{margin:0;padding:0;}

            #auth_code{width:200px;

                       height:100px;

                       border:1px solid #ccc;

                       margin:200px auto 0;

                       text-align:center;

                       line-height:100px;

                       font-size:50px;

                       letter-spacing:5px;

                       cursor:pointer;}

        </style>

    </head>

    <body>

        <div id="auth_code" onclick="auth_code()"></div>

        <script>

            //验证码内需要字符个数

            var num=4;

            //点击更换验证码

            function auth_code(){

                //获取id为box元素

                var box=$("auth_code");

                //随机改变字符

                box.innerHTML=randstr();

                //获取box里span元素，并换颜色

                for(var i=0;i<num;i++){

                    var span=box.getElementsByTagName("span")[i];

                    span.style.color=randcolor16();

                }

            }

            //获取元素通过ID-----------函数-----------

            function $(IdName){

                return document.getElementById(IdName);

            }

            //字符随机选取---------------函数------------

            function randstr(){

                var all = ['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'];

                var words="";

                for(var i=0;i<num;i++){

                    var word=all[parseInt(Math.random()*all.length)];

                    words+="<span>"+word+"</span>";

                }

                return words;

            }

            //随机颜色rgb------------函数----------------

            function randcolor(){

                var color= parseInt(Math.random()*255);

                var color1= parseInt(Math.random()*255);

                var color2= parseInt(Math.random()*255);

                return "rgb("+color+","+color1+","+color2+")"

            }

            //随机颜色十六进制-----------函数------------------

            function randcolor16(){

                var color="#";

                var color16num = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f']

                for(var i=1; i<=6;i++){

                    color+=color16num[parseInt(Math.random()*color16num.length)]

                }

                return color;

            }

            window.onload = auth_code();

        </script>

    </body>

</html>