<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body onload="startTime()">
<div id="txt"></div>
<script>
function startTime() {
var today = new Date();
var h = today.getHours();
var m = today.getMinutes();
var s = today.getSeconds();
// 在 numbers<10 的数字前加上 0
m = checkTime(m);
s = checkTime(s);
document.getElementById("txt").innerHTML = h + ":" + m + ":" + s;
var t = setTimeout(function(){ startTime() }, 500);
}
function checkTime(i) {
if (i < 10) {
i = "0" + i;
}
return i;
}
</script>
</body>
</html>