<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
#div1{
width: 220px;
height: 300px;
background: gray;
margin: 100px auto;
border: 1px solid red;
text-align: center
}
#div1 div{
background: orange;
width: 220px;
height: 50px;
margin: 40px auto;
text-align: center;
line-height: 50px;
font-size: 24px;
color:white;
}
#div1 button{
width: 80px;
height: 30px;
margin: 5px;
font-size: 15px;
color: orange;
}
</style>
</head>
<body>
<div id = "div1">
<div id="time"></div>
<button onclick = "startClick();">开始</button><br />
<button onclick = "pauseClick();">暂停</button><br />
<button onclick = "stopClick();">重置</button>
</div>
</body>
</html>
<script>
var oTime = document.getElementById("time");
oTime.innerHTML = "00:00:00:000";
var h=0,m=0,s=0,t=0,timer=null;
function startClick(){
clearInterval(timer);//先去掉上一次的定时器，以防止连续按两次及以上的开始出现速度越来越快的情况，因为开了多个定时器
timer = setInterval(function(){
t= Number(t)+10;
if(t>=1000){
s++;
t = 0;
}
if(s>60){
m++;
s = 0;
}
if(m>60){
h++;
m = 0;
}
if(t<10){
t = "00"+t;
}else if(t<100){
t = "0"+t;
}
console.log(t)
oTime.innerHTML = bZero(h)+":"+bZero(m)+":"+bZero(s)+":"+t;
},10)
}
function pauseClick(){
clearInterval(timer);
}
function stopClick(){
clearInterval(timer);
oTime.innerHTML = "00:00:00:000";
h=0,m=0,s=0,t=0
}
function bZero(n){
if(n<10){
return "0"+n;
}
return n;
}
</script>
