How can I set a delay of 5 seconds when the timer hits 00:00?

Question

I'm setting up a countdown timer to an application, and when this countdown hits the mark of 00:00 I want to have 5 seconds of delay before it restarts counting down again. How can i use setTimeout() to make it?

function startTimer(duration, display) {
    var timer = duration, minutes, seconds;
    setInterval(function () {
            minutes = parseInt(timer / 60, 10);
            seconds = parseInt(timer % 60, 10);

            minutes = minutes < 10 ? "0" + minutes : minutes;
            seconds = seconds < 10 ? "0" + seconds : seconds;

           display.textContent = minutes + ":" + seconds;

            if (--timer < 0) {
                timer = duration;
            }
    }, 1000);
    duration = timer;
}

Answer 1

The interval will continue ticking until you clear it, so what you need to do is when the timer hits zero, clear the interval and then set a timeout that will restart the interval. (In order to clear an interval, you need to store its returned handle in a variable first.) A bit of recursion can help here:

function startTimer(duration, display) {
  var timer = duration, minutes, seconds;
  var timerInterval = setInterval(function () {
    minutes = parseInt(timer / 60, 10);
    seconds = parseInt(timer % 60, 10);

    minutes = minutes < 10 ? "0" + minutes : minutes;
    seconds = seconds < 10 ? "0" + seconds : seconds;

    display.textContent = minutes + ":" + seconds;

    if (--timer < 0) {
        window.clearInterval(timerInterval);
        window.setTimeout(() => startTimer(duration, display), 5000);
    }
  }, 1000);
}