JS实现页面计时

前言
计时功能在网页上是非常多的，现在我就用原生JS做个计时功能吧
HTML

<div><label>得到毫</label>
	<h5></h5>
</div>
<div><label>得到秒</label>
	<h4></h4>
</div>
<div><label>得到分</label>
	<h3></h3>
</div>
<div><label>得到时</label>
	<h2></h2>
</div>
<div><label>得到天</label>
	<h1></h1>
</div>

var StarTime = new Date().getTime();

			setInterval(function() {
				NotRetain();
			}, 500)
			
			function Retain() {
				//保留小数点
				var NowTime = new Date().getTime();
				//毫
				document.querySelectorAll("h5")[0].innerHTML = NowTime - StarTime + "毫秒";
				//秒
				document.querySelectorAll("h4")[0].innerHTML = (NowTime - StarTime) / 1000  + "秒"
				//分
				document.querySelectorAll("h3")[0].innerHTML = (NowTime - StarTime) / (1000 * 60)  + "分"
				//时
				document.querySelectorAll("h2")[0].innerHTML = (NowTime - StarTime) / (1000 * 60 * 60) + "时"
				//天
				document.querySelectorAll("h1")[0].innerHTML = (NowTime - StarTime) / (1000 * 50 * 60 * 24) + "天"
			}
			
			function NotRetain() {
				//不保留小数点
				var NowTime = new Date().getTime();
				//毫
				document.querySelectorAll("h5")[0].innerHTML = NowTime - StarTime + "毫秒";
				//秒
				document.querySelectorAll("h4")[0].innerHTML = parseInt((NowTime - StarTime) / 1000)  + "秒"
				//分
				document.querySelectorAll("h3")[0].innerHTML = parseInt((NowTime - StarTime) / (1000 * 60))  + "分"
				//时
				document.querySelectorAll("h2")[0].innerHTML = parseInt((NowTime - StarTime) / (1000 * 60 * 60)) + "时"
				//天
				document.querySelectorAll("h1")[0].innerHTML = parseInt((NowTime - StarTime) / (1000 * 50 * 60 * 24)) + "天"
			}

效果
保留小数点
在这里插入图片描述
不保留小数点

完整代码

<html>
	<head>
		<meta charset="utf-8" />
		<title>JS实现页面计时</title>
	</head>
	<body>
		<div><label>得到毫</label>
			<h5></h5>
		</div>
		<div><label>得到秒</label>
			<h4></h4>
		</div>
		<div><label>得到分</label>
			<h3></h3>
		</div>
		<div><label>得到时</label>
			<h2></h2>
		</div>
		<div><label>得到天</label>
			<h1></h1>
		</div>
		<script>
			var StarTime = new Date().getTime();

			setInterval(function() {
				Retain();
			}, 500)
			
			function Retain() {
				//保留小数点
				var NowTime = new Date().getTime();
				//毫
				document.querySelectorAll("h5")[0].innerHTML = NowTime - StarTime + "毫秒";
				//秒
				document.querySelectorAll("h4")[0].innerHTML = (NowTime - StarTime) / 1000  + "秒"
				//分
				document.querySelectorAll("h3")[0].innerHTML = (NowTime - StarTime) / (1000 * 60)  + "分"
				//时
				document.querySelectorAll("h2")[0].innerHTML = (NowTime - StarTime) / (1000 * 60 * 60) + "时"
				//天
				document.querySelectorAll("h1")[0].innerHTML = (NowTime - StarTime) / (1000 * 50 * 60 * 24) + "天"
			}
			
			function NotRetain() {
				//不保留小数点
				var NowTime = new Date().getTime();
				//毫
				document.querySelectorAll("h5")[0].innerHTML = NowTime - StarTime + "毫秒";
				//秒
				document.querySelectorAll("h4")[0].innerHTML = parseInt((NowTime - StarTime) / 1000)  + "秒"
				//分
				document.querySelectorAll("h3")[0].innerHTML = parseInt((NowTime - StarTime) / (1000 * 60))  + "分"
				//时
				document.querySelectorAll("h2")[0].innerHTML = parseInt((NowTime - StarTime) / (1000 * 60 * 60)) + "时"
				//天
				document.querySelectorAll("h1")[0].innerHTML = parseInt((NowTime - StarTime) / (1000 * 50 * 60 * 24)) + "天"
			}
		</script>
	</body>
</html>

后言
本文结束了，如果觉得本技术文章对你有帮助请给我点个赞,如果有什么不足的地方，给我提意见，让我加以改进