本文实例为大家分享了JS实现随机生成验证码的具体代码，供大家参考，具体内容如下
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<style>
</style>
</head>
<body>
<div>
<h1>111111</h1><a href="#" rel="external nofollow" >看不清换一张</a>
</div>
验证码：<input type="text" value="" />
<button>确定</button>
</body>
<script>
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];
var h1=document.querySelector("h1");
var btn=document.querySelector("button");
var change=document.querySelector("a");
var input=document.querySelector("input");
function fn(){
var arr1=Math.floor(Math.random()*62);
var arr2=Math.floor(Math.random()*62);
var arr3=Math.floor(Math.random()*62);
var arr4=Math.floor(Math.random()*62);
var arr5=Math.floor(Math.random()*62);
var arr6=Math.floor(Math.random()*62);
var yz=""+arr[arr1]+arr[arr2]+arr[arr3]+arr[arr4]+arr[arr5]+arr[arr6];
h1.innerHTML=yz;
btn.onclick=function(){
alert(input.value);
if(input.value==yz){
alert("正确");
}else{
alert("错误");
}
}
}
fn();
change.addEventListener("click",fn);
</script>
</html>
1、Math.floor(） 方法
Math.floor(x）
floor() 方法返回小于等于x的最大整数。
如果传递的参数是一个整数，该值不变。
2、Math.random()方法
random() 方法可返回介于 0（包含） ~ 1（不包含） 之间的一个随机数。
使用以上两种方法可以实现取随机数的功能
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猪先飞。
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