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;i< 123 ;i++){
if(i>57 && i< 65 ) continue;
if(i>90 && i< 97 ) 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服务器之家。
原文链接：https://blog.csdn.net/are_gh/article/details/112004087
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