<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script type="text/javascript">
function ValPwd(){
var a = document.getElementById("password").value;
console.log(a);
var b = document.getElementById("password_again").value;
console.log(b);
if(a==""){
alert("请输入密码");
}
else if(a!=""&&a==b){
alert("密码正确");
}else{
alert("密码不一致");
}
}
</script>
</head>
<body>
<input type="password" id="password" placeholder="请输入密码"/><br />
<input type="password" id="password_again" placeholder="请再次输入密码"/><br />
<button onclick="ValPwd()">登录</button>
</body>
</html>
原文：https://www.cnblogs.com/zdy-123/p/10441336.html