kennyray/gist:b35f4c6640be9539c5d16581de7714e0

## gistfile1.txt

class CountdownTimer {

	constructor(minutesLabel = null, secondsLabel = null) {
		this.minutesLabel = minutesLabel;
		this.secondsLabel = secondsLabel;
		this.totalSeconds = (this.minutesLabel.textContent / 60) + this.secondsLabel.textContent;
		this.timer = null;
	}

	set minutesLabel(value) {
		this._minutesLabel = value;
	}

	set secondsLabel(value) {
		this._secondsLabel = value;
	}

	get minutesLabel() {
		return this._minutesLabel;
	}

	get secondsLabel() {
		return this._secondsLabel;
	}


    setTime() {
      this.totalSeconds--;
	  if (parseInt(this.minutesLabel.innerHTML) == 0 && parseInt(this.secondsLabel.innerHTML) == 0) { this.stopTimer; return;}

	  if (this.secondsLabel.innerHTML.textContent < 0) { this.secondsLabel.innerHTML = 59 }
	  if (this.minutesLabel.innerHTML.textContent < 0) { this.minutesLabel.innerHTML = 59 }
	  this.secondsLabel.innerHTML = this.pad((this.totalSeconds % 60));
      this.minutesLabel.innerHTML = this.pad(Math.floor(this.totalSeconds / 60));

    }

	pad(val) {
    		var valString = val + "";
        if (valString.length < 2) {
            return "0" + valString;
		} else {
            return valString;
        }
    }

    resetTimer() {
        clearInterval(this.timer);
        this.totalSeconds = 0;
        this.secondsLabel.innerHTML = this.pad(this.totalSeconds % 60);
        this.minutesLabel.innerHTML = this.pad(parseInt(this.totalSeconds / 60));
    }

    startTimer() {
    	this.timer = setInterval(this.setTime.bind(this), 1000);
    }

	stopTimer() {
    	clearInterval(this.timer);
    }

}


<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>Countdown Timer</title>
  <script src="countdown_timer2.js"></script>
</head>
<body>
<label id="minutes1">00</label>:<label id="seconds1">10</label>
<br>
<label id="minutes">00</label>:<label id="seconds">09</label>
<script>

const t1 = new CountdownTimer(document.getElementById("minutes1"), document.getElementById("seconds1"));
//t1.startTimer();


const t2 = new CountdownTimer(document.getElementById("minutes"), document.getElementById("seconds"));
console.log(t1.startTimer() === t2.startTimer());
t2.startTimer();

</script
</body>
</html>

	class CountdownTimer {

	constructor(minutesLabel = null, secondsLabel = null) {
	this.minutesLabel = minutesLabel;
	this.secondsLabel = secondsLabel;
	this.totalSeconds = (this.minutesLabel.textContent / 60) + this.secondsLabel.textContent;
	this.timer = null;
	}

	set minutesLabel(value) {
	this._minutesLabel = value;
	}

	set secondsLabel(value) {
	this._secondsLabel = value;
	}

	get minutesLabel() {
	return this._minutesLabel;
	}

	get secondsLabel() {
	return this._secondsLabel;
	}


	setTime() {
	this.totalSeconds--;
	if (parseInt(this.minutesLabel.innerHTML) == 0 && parseInt(this.secondsLabel.innerHTML) == 0) { this.stopTimer; return;}

	if (this.secondsLabel.innerHTML.textContent < 0) { this.secondsLabel.innerHTML = 59 }
	if (this.minutesLabel.innerHTML.textContent < 0) { this.minutesLabel.innerHTML = 59 }
	this.secondsLabel.innerHTML = this.pad((this.totalSeconds % 60));
	this.minutesLabel.innerHTML = this.pad(Math.floor(this.totalSeconds / 60));

	}

	pad(val) {
	var valString = val + "";
	if (valString.length < 2) {
	return "0" + valString;
	} else {
	return valString;
	}
	}

	resetTimer() {
	clearInterval(this.timer);
	this.totalSeconds = 0;
	this.secondsLabel.innerHTML = this.pad(this.totalSeconds % 60);
	this.minutesLabel.innerHTML = this.pad(parseInt(this.totalSeconds / 60));
	}

	startTimer() {
	this.timer = setInterval(this.setTime.bind(this), 1000);
	}

	stopTimer() {
	clearInterval(this.timer);
	}

	}


	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width">
	<title>Countdown Timer</title>
	<script src="countdown_timer2.js"></script>
	</head>
	<body>
	<label id="minutes1">00</label>:<label id="seconds1">10</label>
	<br>
	<label id="minutes">00</label>:<label id="seconds">09</label>
	<script>

	const t1 = new CountdownTimer(document.getElementById("minutes1"), document.getElementById("seconds1"));
	//t1.startTimer();


	const t2 = new CountdownTimer(document.getElementById("minutes"), document.getElementById("seconds"));
	console.log(t1.startTimer() === t2.startTimer());
	t2.startTimer();

	</script
	</body>
	</html>