JSFiddle - React, Tailwind, and code Playground

HTML

<div id="foo"> </div>
<input type="checkbox" />

JavaScript

function fooFunc() {
    $('#foo').text(+new Date());
}
var id;
var shouldBeStopped = false;
$('input').change(function() {
    if (shouldBeStopped) 
        clearInterval(id);
    else 
        id = setInterval(fooFunc, 200);

    shouldBeStopped = !shouldBeStopped;
});