<!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>四位隨機驗證碼</title>
<script>
// function yan() {
// var number = document.getElementById("number");
// var num = parseInt(Math.random() * 10000);//有bug.
// //alert(1);
// //alert(num);
// //num = 9527;
// console.log(num);
// number.value = num;
// }
// //yan();
window.onload = function () {
but.onclick = function yan() {//點擊事件 觸發
var but = document.getElementById("btn");//獲取元素
var num = document.getElementById("number");
var numb = num.value;
//console.log(num1);
var html = "";//驗證碼初始值
for (var i = 0; i < 4; i++) {
html += parseInt(Math.random() * 10);//循環四次 對得出的數字進行拼接
}
// console.log(html);
num.value = html;//寫入到文本框中
var but2 = document.getElementById("but2");
var num1 = document.getElementById("number2");
but2.onclick = function () {
var num2 = num1.value;
//console.log(num2);
if (num2 == num.value) { //判斷生成的驗證碼和輸入的驗證碼是否相同
//location.href = "index.html"; //不會在新的窗口打開，會覆蓋原網頁的內容
window.open("index.html");//在新的網頁打開 和a標簽的的blank屬性相似。
} else {
alert("請帶好您的眼鏡，謝謝配合。");//提示錯誤信息
}
}
}
}
</script>
</head>
<body>
<input type="text" id="number">
<input type="button" value="點擊生成驗證碼" id="but" onclick="yan()">
<br>
<input type="text" id="number2">
<input type="button" value="確定" id="but2">
</body>
</html>