JSFiddle - React, Tailwind, and code Playground

by Brock Callahan

HTML

<pre>
<h1>One minute timer</h1>
<div id="timeDisplay"></div>
<button id="startTimer">Start</button>
</pre>

JavaScript

var display = document.getElementById("timeDisplay");
var tick;
var i;

document.getElementById("startTimer").onclick = function() {
    // Make sure timer isn't already running
    clearInterval(tick);
    // Change button text
    document.getElementById("startTimer").innerText = "Re-start";
    // Initializer
    i = 1;
    // Start timer
    tick = setInterval(function() {
        if (i >= 60) {
            clearInterval(tick);
            display.innerText = "Time up.";
        } else {
            display.innerText = i;
            i++;
            return;
        }
    }, 1000);
};