JSFiddle - React, Tailwind, and code Playground

by Luke Marlow

HTML

<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
<div id="output"></div>

JavaScript

var track_time  = '31',
		time_parts  = track_time.split(':'),
    return_time = '';

if (parseInt(time_parts.length) === 1) {
		return_time += "00:00:";
    return_time += ("00" + time_parts[0]).slice(-2);
}
else if (parseInt(time_parts.length) === 2) {
		return_time += '00:';
  	return_time += ("00" + time_parts[0]).slice(-2) + ":";
  	return_time += ("00" + time_parts[1]).slice(-2);
}
else if (parseInt(time_parts.length) === 3) {
		return_time + ("00" + time_parts[0]).slice(-2) + ":";
		return_time + ("00" + time_parts[1]).slice(-2) + ":";
		return_time + ("00" + time_parts[2]).slice(-2);
}

$('#output').html(return_time);