javascript - 简单倒计时器mm :ss

Question

我想创建一个简单的倒计时器。

我发现了一些东西，它工作了几小时、几分、几秒，我只想要分:秒...

如何为 mm:ss 格式制作相同的计时器？

var seconds;
var temp;

function countdown() {
     time = document.getElementById('countdown').innerHTML;
     timeArray = time.split(':')
     seconds = timeToSeconds(timeArray);

     if (seconds == '') {
          temp = document.getElementById('countdown');
          temp.innerHTML = "00:00:00";
          return;
     }

     seconds--;

     temp = document.getElementById('countdown');
     temp.innerHTML = secondsToTime(seconds);
     timeoutMyOswego = setTimeout(countdown, 1000);
}

function timeToSeconds(timeArray) {
     var minutes = (timeArray[0] * 60) + (timeArray[1] * 1);
     var seconds = (minutes * 60) + (timeArray[2] * 1);
     return seconds;
}

function secondsToTime(secs) {
     var hours = Math.floor(secs / (60 * 60));
     hours = hours < 10 ? '0' + hours : hours;

     var divisor_for_minutes = secs % (60 * 60);
     var minutes = Math.floor(divisor_for_minutes / 60);
     minutes = minutes < 10 ? '0' + minutes : minutes;

     var divisor_for_seconds = divisor_for_minutes % 60;
     var seconds = Math.ceil(divisor_for_seconds);
     seconds = seconds < 10 ? '0' + seconds : seconds;
     return hours + ':' + minutes + ':' + seconds;
}

countdown();

这是 html

<div id="countdown">01:02:15</div>

Answer 1

    var seconds;  
    var temp;
    console.clear();

    function countdown() {
         time = document.getElementById('countdown').innerHTML;
         timeArray = time.split(':')
         seconds = timeToSeconds(timeArray);

         if (seconds == '') {
              temp = document.getElementById('countdown');
              temp.innerHTML = "00:00";

              return;
         }
         seconds--;
         temp = document.getElementById('countdown');
         temp.innerHTML= secondsToTime(seconds);
         timeoutMyOswego = setTimeout(countdown, 1000);        
    }

    function timeToSeconds(timeArray) {  
         var minutes = (timeArray[0] * 1);
         var seconds = (minutes * 60) + (timeArray[1] * 1);
         return seconds;
    }

    function secondsToTime(secs) {
         var hours = Math.floor(secs / (60 * 60));
         hours = hours < 10 ? '0' + hours : hours;
         var divisor_for_minutes = secs % (60 * 60);
         var minutes = Math.floor(divisor_for_minutes / 60);
         minutes = minutes < 10 ? '0' + minutes : minutes;
         var divisor_for_seconds = divisor_for_minutes % 60;
         var seconds = Math.ceil(divisor_for_seconds);
         seconds = seconds < 10 ? '0' + seconds : seconds;            
         return  minutes + ':' + seconds;   
    }

    countdown();

https://jsfiddle.net/santoshj/jex1f8uv/