JSFiddle - React, Tailwind, and code Playground

HTML

<button name="start">Start</button>
<button name="end">End</button>
<div></div>

JavaScript

var myInterval;

$('button[name="start"]').click(function(){
	myInterval = setInterval(function(){
    	$('body div').prepend('Oh Hai! ');
    },1000);
});

$('button[name="end"]').click(function(){
	clearInterval(myInterval);
});