Page countdown to achieve the effect:
Page countdown to achieve effect
code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>页面倒计时</title>
<style>
* {
margin: 0;
padding: 0;
}
.timer {
width: 300px;
margin: 50px auto;
}
.timer > * {
float: left;
}
.hour, .min, .sec {
width: 45px;
height: 45px;
background-color: #605157;
font-size: 24px;
text-align: center;
line-height: 45px;
color: #fff;
}
.s {
height: 45px;
text-align: center;
line-height: 45px;
font-size: 24px;
width: 20px;
}
</style>
</head>
<body>
<div class="timer">
<div class="hour" id="hour"></div>
<div class="s">:</div>
<div class="min" id="min"></div>
<div class="s">:</div>
<div class="sec" id="sec"></div>
</div>
<script>
//获取要操作的dom
var hour = document.getElementById('hour');
var min = document.getElementById('min');
var sec = document.getElementById('sec');
// 倒计时时长 单位是s
var t = 78;
// 实现过程，反复做，间隔定时器
var tid = setInterval(function(){
t --;
// 1. 根据时间计算时分秒
var s = parseInt(t /3600 );
var f = parseInt((t % 3600) / 60);
var m = t % 60;
// 2. 把时分秒放到页面中（格式化）
hour.innerText = format(s);
min.innerText = format(f);
sec.innerText = format(m);
// 停止
if (t == 0){
clearInterval(tid);
}
}, 1000);
// 格式化时间， 0 -》 00
function format(num){
if (num < 10) {
return '0' + num;
}
return '' + num;
}
</script>
</body>
</html>