JSFiddle - React, Tailwind, and code Playground
HTML
<div id="text">wut</div>
<div id="result"></div>
JavaScript
var changeIt = function(){
$('#text').text('what');
};
setTimeout(changeIt, 2e3);
var orig_text = $('#text').text(),
poller = function(){
var new_text = $('#text').text();
if(new_text !== orig_text){
$('#result').text('it\'s changed');
}
setTimeout(poller, 1);
};
poller();