今天朋友让我帮忙敲一个作业，随便输入一个时间然后计算与今天相差多少天，当做回顾一下Date
html：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<script src="./js/main.js"></script>
<link href="./css/index.css" target="_blank" rel="external nofollow" rel="stylesheet">
</head>
<body>
<div class="panel bigtitle">当前时间：<span id="time1"></span></div>
<div class="panel">
<div class="assert">年</div>
<div class="inputresult">
<input type="text" id="year1" class="inputtext" />
</div>
<div class="assert">月</div>
<div class="inputresult">
<input type="text" id="month1" class="inputtext" />
</div>
<div class="assert">日</div>
<div class="inputresult">
<input type="text" id="day1" class="inputtext" />
</div>
</div>
<div class="panel">
<input type="button" value="计算" class="onebutton" id="button1" onclick="click1()" />
</div>
<div>计算结果
<span id="cal"></span><span>"天"</span>
</div>
</body>
</html>
<script>
//这个地方是想获取当前时间用来展示的
var date = new Date()
var year = date.getFullYear();
var month = date.getMonth() + 1;
var day = date.getDate();
var time = document.getElementById("time1");
time.innerHTML = (year + "/" + month + "/" + day);
//计算代码
function click1() {
//获取到input里面的值
var month1 = document.querySelector("#month1").value;
var year1 = document.querySelector("#year1").value;
var day1 = document.querySelector("#day1").value;
var t1 = year1 + "/" + month1 + "/" + day1;
var dateBegin = new Date(t1); //可以把“2020/12/8"转化成“Tue Dec 08 2020 00:00:00 GMT+0800 (中国标准时间)”
var date = new Date();
var result = date.getTime() - dateBegin.getTime();
var a = Math.floor(result / (24 * 3600 * 1000));
document.querySelector('#cal').innerHTML = a;
}
</script>
这里需要注意getTime()，他获取时间戳的方法和时区有关，所以有关时间的参数还是找后端要
回顾：
getTime() 方法可返回距 1970 年 1 月 1 日之间的毫秒数。
getFullYear() getMonth() getDate() 返回年月日
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