Javascript秒倒计时

Question

我已经尝试了几个小时来制作一个 javascript 函数，该函数将以秒为单位输入时间并提供倒计时。出于某种原因，它只是在第一秒后拒绝倒计时，我不明白为什么不这样做。

这是我的 HTML:

<span style="display:none;" id="unixtime_coming_0">600</span><span onload='timer()' id="timer_coming_0"></span>

这是我的 javascript:

setInterval(function timer() {
  var count = document.getElementById("unixtime_coming_0").innerHTML;
  count = count - 1;
  if (count <= 0) {
    clearInterval(counter);
    return;
  }
  var days = Math.floor(count / 86400);
  var hours = Math.floor(count / 3600) % 24;
  var minutes = Math.floor(count / 60) % 60;
  var seconds = count % 60;
  document.getElementById("timer_coming_0").innerHTML = days + "d " + hours + "h " + minutes + "m " + seconds + "s"; // watch for spelling
}, 1000);

Answer 1

定义命名函数不返回任何内容。您必须在 setInterval 之外定义它:

var counter = setInterval(timer, 1000);

function timer() {
    var unixtime = document.getElementById("unixtime_coming_0");
    var count = parseInt(unixtime.innerHTML, 10);
    unixtime.innerHTML = count - 1;

    if (count < 1) {
        clearInterval(counter);
        return;
    }

    var days = Math.floor(count / 86400);
    var hours = Math.floor(count / 3600) % 24;
    var minutes = Math.floor(count / 60) % 60;
    var seconds = count % 60;

    document.getElementById("timer_coming_0").innerHTML= days + "d " + hours + "h " + minutes + "m " + seconds + "s"; // watch for spelling
}

我会完全摆脱 setInterval。只需在 timer 本身内部通过 setTimeout 调用 timer。