getTime出來的單位是毫秒數（某日期離現在共幾天）－Bug倉庫 // 程式日記

Sep 01 Fri 2017 14:08
getTime出來的單位是毫秒數（某日期離現在共幾天）

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<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
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<body>
	<h2>輸入<input type="date" id="usertype"><button id="btn">所以結果是</button>
	<br>
	這天離現在共有</h2>
	<h2><span id="differday"></span>天</h2>
	

	<script type="text/javascript">
		document.getElementById('btn').onclick=function(){
			var usertype=document.getElementById('usertype').value;
			var usertypetoobj=new Date(usertype);
			var today=new Date();
			var difference=today.getTime()-usertypetoobj.getTime();
			/*毫秒數換算*/
			var howManyDay=Math.floor(difference/(1000*60*60*24));
			document.getElementById('differday').textContent=howManyDay;
		}
	</script>
</body>
</html>