js实现的简单计时器和闹钟的部分功能,主要利用Date()对象和math对象,还有一个定时器setInterval()
1 <!DOCTYPE html>
2 <html>
3 <head>
4 <meta charset="utf-8">
5 <title>js实现倒计时</title>
6 <style>
7 div{
8 position:absolute;
9 width:400px;
10 height:50px;
11 left:50%;
12 top:50%;
13
14
15 }
16
17
18
19 span {
20 text-align: center;
21 font-size:40px;
22 }
23
24 </style>
25 </head>
26 <body>
27
28
29 <div id="container">
30
31 <span id="demo"></span>
32
33
34 </div>
35 </body>
36 <script>
37
38 function clock(mytime){
39
40 //设置要倒计时的时间
41 var stime=new Date(mytime).getTime();
42 // 获取目前的时间
43 var ntime=new Date().getTime();
44 var dtime=stime-ntime;
45
46
47 if(dtime>0){//可以在此处设置闹钟
48
49 var days = Math.floor(dtime / (1000 * 60 * 60 * 24));
50 var hours = Math.floor((dtime% (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
51 var minutes = Math.floor((dtime % (1000 * 60 * 60)) / (1000 * 60));
52 var seconds = Math.floor((dtime % (1000 * 60)) / 1000);
53 document.getElementById("demo").innerHTML = days +"天" +hours +"时" + minutes +"分" +seconds +"秒";
54 }
55 else{//闹钟好了
56 var div=document.getElementById("container");
57 var audio=document.createElement("audio");
58 div.appendChild(audio);
59 audio.src="喜相逢.mp3";
60 audio.loop="loop";
61 audio.autoplay="autoplay";
62
63 }
64
65 }
66 //重复调用
67 setInterval(clock,1000)
68 </script>
69 </html>