一:设置时长,进行倒计时。比如考试时间等等
代码如下:
<html> <head> <meta charset="UTF-8"> <title>简单时长倒计时</title> <SCRIPT type="text/javascript"> var maxtime = 60 * 60; //一个小时,按秒计算,自己调整! function CountDown() { if (maxtime >= 0) { minutes = Math.floor(maxtime / 60); seconds = Math.floor(maxtime % 60); msg = "距离结束还有" + minutes + "分" + seconds + "秒"; document.all["timer"].innerHTML = msg; if (maxtime == 5 * 60)alert("还剩5分钟"); --maxtime; } else{ clearInterval(timer); alert("时间到,结束!"); } } timer = setInterval("CountDown()", 1000); </SCRIPT> </head> <body> <div id="timer" style="color:red"></div> <div id="warring" style="color:red"></div> </body> </html>
二:设置时间戳,进行倒计时。比如距离活动结束时间等等
代码如下:
<html> <head> <meta charset="UTF-8"> <title>js简单时分秒倒计时</title> <script type="text/javascript"> function countTime() { //获取当前时间 var date = new Date(); var now = date.getTime(); //设置截止时间 var str="2017/5/17 00:00:00"; var endDate = new Date(str); var end = endDate.getTime(); //时间差 var leftTime = end-now; //定义变量 d,h,m,s保存倒计时的时间 var d,h,m,s; if (leftTime>=0) { d = Math.floor(leftTime/1000/60/60/24); h = Math.floor(leftTime/1000/60/60%24); m = Math.floor(leftTime/1000/60%60); s = Math.floor(leftTime/1000%60); } //将倒计时赋值到div中 document.getElementById("_d").innerHTML = d+"天"; document.getElementById("_h").innerHTML = h+"时"; document.getElementById("_m").innerHTML = m+"分"; document.getElementById("_s").innerHTML = s+"秒"; //递归每秒调用countTime方法,显示动态时间效果 setTimeout(countTime,1000); } </script> </head > <body onload="countTime()" > <div> <span id="_d">00</span> <span id="_h">00</span> <span id="_m">00</span> <span id="_s">00</span> </div> </body> </html>