2种简单的js倒计时方式

//带天数的倒计时function countDown(times){  var timer=null;  timer=setInterval(function(){    var day=0,      hour=0,      minute=0,      second=0;//时间默认值    if(times > 0){      day = Math.floor(times / (60 * 60 * 24));      hour = Math.floor(times / (60 * 60)) - (day * 24);      minute = Math.floor(times / 60) - (day * 24 * 60) - (hour * 60);      second = Math.floor(times) - (day * 24 * 60 * 60) - (hour * 60 * 60) - (minute * 60);    }    if (day <= 9) day = '0' + day;    if (hour <= 9) hour = '0' + hour;    if (minute <= 9) minute = '0' + minute;    if (second <= 9) second = '0' + second;    //    console.log(day+"天:"+hour+"小时："+minute+"分钟："+second+"秒");    times--;  },1000);  if(times<=0){    clearInterval(timer);  }}

//单纯分钟和秒倒计时function resetTime(time){  var timer=null;  var t=time;  var m=0;  var s=0;  m=Math.floor(t/60%60);  m<10&&(m='0'+m);  s=Math.floor(t%60);  function countDown(){   s--;   s<10&&(s='0'+s);   if(s.length>=3){    s=59;    m="0"+(Number(m)-1);   }   if(m.length>=3){    m='00';    s='00';    clearInterval(timer);   }   console.log(m+"分钟"+s+"秒");  }  timer=setInterval(countDown,1000);}