JavaScript 使用 Date 对象实现动态倒计时

代码结构分析

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>倒计时动画</title>
  <style>
    div{
      text-align:center;
      height:100px;
      line-height:100px;
    }
  </style>
  <script>
    window.onload = function(){
      setInterval(FreeTime,1000);
    }
    function FreeTime(){
      var curTime = Date.now();
      var endTime = new Date("2017-10-26 16:00:00");
      var allFreeSeconds = (endTime-curTime)/1000;
      if(allFreeSeconds>0){
        var freeDay = Math.floor(allFreeSeconds/(24*60*60));
        var freeHour = Math.floor(allFreeSeconds/(60*60) % 24);
        var freeMinute = Math.floor(allFreeSeconds/60 % 60);
        var freeSecond = Math.floor(allFreeSeconds%60);
        document.getElementById("nowTime").innerHTML = "剩余"+freeDay+"天"+freeHour+"时"+freeMinute+"分"+freeSecond+"秒";
      }
      else{
        document.getElementById("nowTime").innerHTML = "已结束";
      }
    }
  </script>
</head>
<body>
<div>
  <span id="nowTime"></span>
</div>
</body>
</html>