javascript - 如何四舍五入到仅几秒(删除毫秒)

我正在尝试将下面的倒计时时钟调整为大约几秒，以消除毫秒。

有什么建议吗？

<script type="text/javascript">
  // Set the date we're counting down to
  var countDownDate = new Date("Jan 1, 2018 00:00:01").getTime();


  // Update the count down every 1 second
  var x = setInterval(function() {

    // Get todays date and time
    var now = new Date().getTime();

    // Find the distance between now an the count down date
    var distance = countDownDate - now;

    // Time calculations for days, hours, minutes and seconds
    var days = Math.floor(distance / (1000 * 60 * 60 * 24));
    var hours = Math.floor((distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
    var minutes = Math.floor((distance % (1000 * 60 * 60)) / (1000 * 60));
    var seconds = Math.floor(distance % (1000 * 60)) / (1000)


    // Display the result in the element with id ="timmer"
    document.getElementById("timmer").innerHTML = days + "d " + hours + "h " + minutes + "m " + seconds + "s ";


  }, 1000);
</script>

最佳答案

问题在这里：

var seconds = Math.floor(distance % (1000 * 60)) / (1000);

正确方法：

var seconds = Math.floor(distance % (1000 * 60) / (1000));

为什么？

因为您太早包装Math.floor。

var countDownDate = new Date("Jan 1, 2018 00:00:01").getTime();

// Update the count down every 1 second
var x = setInterval(function(){

    // Get todays date and time
    var now = new Date().getTime();

    // Find the distance between now an the count down date
    var distance = countDownDate - now;

    // Time calculations for days, hours, minutes and seconds
    var days = Math.floor(distance / (1000 * 60 * 60 * 24));
    var hours = Math.floor((distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
    var minutes = Math.floor ((distance % (1000 * 60 * 60)) / (1000 * 60));
    var seconds = Math.floor(distance % (1000 * 60) / (1000));
    // CHANGES HERE ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


    // Display the result in the element with id ="timmer"
    document.getElementById("timmer").innerHTML = days + "d " + hours + "h " + minutes + "m " + seconds + "s ";


}, 1000);

<div id="timmer"></div>

关于javascript - 如何四舍五入到仅几秒(删除毫秒)，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/47570410/