直接上代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<div>
<span id="h">00</span>
<span>:</span>
<span id="m">00</span>
<span>:</span>
<span id="s">10</span>
</div>
<script type="text/javascript">
function setId(id) {
return document.getElementById(id);
}
var hText = setId(‘h‘);
var mText = setId(‘m‘);
var sText = setId(‘s‘);
var timer;
var hour =parseInt(hText.innerHTML);
var min = parseInt(mText.innerHTML);
var sec = parseInt(sText.innerHTML);
var all = hour * 60 * 60 + min * 60 + sec;
function time() {
all--;
h = Math.floor(all / 60 / 60 % 24);
m = Math.floor(all / 60 % 60);
s = Math.floor(all % 60);
if (all > 0) {
hText.innerHTML = isZero(h);
mText.innerHTML = isZero(m);
sText.innerHTML = isZero(s);
} else {
hText.innerHTML = ‘00‘;
mText.innerHTML = ‘00‘;
sText.innerHTML = ‘00‘;
clearInterval(timer);
}
}
function isZero(num) {
return num < 10 ? ‘0‘ + num : num
}
timer = setInterval(time, 1000);
</script>
</body>
</html>