Code and Stuff

A simple method for formatting a timer in Javascript

by Don on August 17, 2020 underjavascriptprogrammingreact

I’ve been working on a React Native project to make an interval timer for working out. The purpose of this is not only so I can become more familiar with working with React Native, but also because I needed a timer that better suited my needs while doing heavy bag workouts. It seemed like a decent project, since it’d deal not only with creating a user interface with React Native, but also dealing with user interaction, saving and loading data, playing sounds and so on.

Anyway, naturally you have to be able to display the time for this sort of thing, and it feels like I’m always needing to do something like this. So here’s the simple function I’m using.

formatAsTime = (number) => {
    let seconds = number / 1000;
    let minutes = parseInt( seconds / 60 );
    seconds = seconds % 60;

    let displayTime = minutes.toString().padStart(2, '0') + ":" + seconds.toString().padStart(2, '0');

    return displayTime;

© 2021 Don Walizer Jr