JSFiddle - React, Tailwind, and code Playground

by Justin Breen

HTML

<div id="one"></div>
<div id="two"></div>
<div id="three"></div>

JavaScript

function isElement(element) {
    return element instanceof Element || element instanceof HTMLDocument;
}

var two = document.querySelector( '#two' );
// var two = 'string';

if ( isElement( two ) ) {
	alert( 'foo' );
} else {
  alert( 'bar' );
}