说明： 方法1， 方法二是基础原理版，方法三升级版（参考for循环，定时器，闭包混合一块的那点事。）
方法一：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>倒计时</title>
</head>
<body>
<div id="timer1" style="color:red"></div>
<div id="timer2" style="color:red"></div>
</body>
<script>
function countDown( maxtime,fn ) {
var timer = setInterval(function() {
if( !!maxtime ){
var day = Math.floor(maxtime / 86400),
hour = Math.floor((maxtime % 86400) / 3600),
minutes = Math.floor((maxtime % 3600) / 60),
seconds = Math.floor(maxtime%60),
msg = "距离结束还有"+day+"天"+hour+"时"+minutes+"分"+seconds+"秒";
fn( msg );
--maxtime;
} else {
clearInterval( timer );
fn("时间到，结束!");
}
}, 1000);
}
countDown( 86,function( msg ) {
document.getElementById('timer1').innerHTML = msg;
})
countDown( 86400,function( msg ) {
document.getElementById('timer2').innerHTML = msg;
})
</script>
</html>
方法二：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>倒计时</title>
</head>
<body>
<div id="timer1"></div>
<div id="timer2"></div>
<div id="timer3"></div>
</body>
<script type="text/javascript">
var addTimer = function () {
var list = [],
interval;
return function (id, time) {
if (!interval)
interval = setInterval(go, 1000);
list.push({ ele: document.getElementById(id), time: time });
}
function go() {
for (var i = 0; i < list.length; i++) {
list[i].ele.innerHTML = getTimerString(list[i].time ? list[i].time -= 1 : 0);
if (!list[i].time)
list.splice(i--, 1);
}
}
function getTimerString(time) {
var not0 = !!time,
d = Math.floor(time / 86400),
h = Math.floor((time %= 86400) / 3600),
m = Math.floor((time %= 3600) / 60),
s = time % 60;
if (not0)
return "还有" + d + "天" + h + "小时" + m + "分" + s + "秒";
else return "时间到";
}
} ();
addTimer("timer1", 12);
addTimer("timer2", 10);
addTimer("timer3", 13);
</script>
</html>
方法三：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>倒计时</title>
</head>
<body>
<div id="timer0" style="color:red"></div>
<div id="timer1" style="color:red"></div>
<div id="timer2" style="color:red"></div>
</body>
<script>
function countDown( maxtime,fn ) {
var timer = setInterval(function() {
if( !!maxtime ){
var day = Math.floor(maxtime / 86400),
hour = Math.floor((maxtime % 86400) / 3600),
minutes = Math.floor((maxtime % 3600) / 60),
seconds = Math.floor(maxtime%60),
msg = "距离结束还有"+day+"天"+hour+"时"+minutes+"分"+seconds+"秒";
fn( msg );
--maxtime;
} else {
clearInterval( timer );
fn("时间到，结束!");
}
}, 1000);
}
var aTime = [3600,3800,3900];
for ( var i = 0; i < 3; i++ ) {
(function (i) {
var obj = 'timer' + i;
countDown( aTime[i],function( msg ) {
document.getElementById(obj).innerHTML = msg;
})
})(i)
}
</script>
</html>
更多关于倒计时的文章请查看专题：《倒计时功能》
更多JavaScript时钟特效点击查看：JavaScript时钟特效专题
