Question

我正在处理一段代码，该代码需要在每次运行时显示时间。现在，当它需要为10:01:01时，它显示的时间为10：1：1。

如果我的分钟或秒数是<10，如何添加0？

<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style type="text/css">
 	html, body {
        margin: 0;
        padding: 0;
        width: 100%;
        height: 100; 
        color: #FFFFFF;
        font-family: Open Sans;
        font-weight: 700;
        font-size: 24px;
        background: #d70080; 
      }

    div {
        position: absolute;
        top: 30%;
        width: 100%;
        text-align: center;
      }
</style>

</head>
	<body>
		<script type="application/javascript">

		function BroadSignPlay(){
		var dd2 = new Date();var hh = dd2.getHours();var mm = dd2.getMinutes();var ss = dd2.getSeconds();
		var data2 = "De tijd is nu: " + hh + ":" + mm + ":" + ss;
		document.getElementById( "DivBroadSignPlay" ).innerHTML =  data2;
		}

		if (top.location != location) {
		top.location.href = location.href;
		}
</script>
	<div id="DivBroadSignPlay"> </div>
	</body>
</html>

Answer 1

使用String.prototype.padStart(2, '0')。要对数字进行字符串化以在其上呼叫padStart，请先在其上呼叫toString()，或使用模板字符串：

function showTime(){
  const date = new Date();
  const hh = date.getHours();
  const mm = date.getMinutes();
  const ss = date.getSeconds();
  const str = [hh, mm, ss].map(x => `${x}`.padStart(2, '0')).join(':');
  document.getElementById('time').innerHTML = str;
}

showTime();
setInterval(showTime, 1000);

<div id="time"></div>

Answer 2

要获取前导零，可以使用"0" + string，然后使用带有负起始值-c的{{3}}来获取最后的c个字符。

function BroadSignPlay(){
  var date = new Date();
  var hh = date.getHours();
  var mm = date.getMinutes();
  var ss = date.getSeconds();
  var arr = [];
  [hh,mm,ss].forEach(function(x){arr.push(getleadingZero(x))});
  
  document.getElementById('DivBroadSignPlay').innerHTML = "De tijd is nu " + arr.join(':');
}

function getleadingZero(v) {
  return ("0" + v).slice(-2);
}

setInterval(BroadSignPlay, 1000);

<div id="DivBroadSignPlay"></div>

如何在分钟和秒数上加上0？

2 个答案: