JSFiddle - React, Tailwind, and code Playground

by FlameTrap

HTML

<div id="a">
    <div id="b">
        <div id="c">
            <div id="d"></div>
        </div>
    </div>
</div>

JavaScript

var a = document.getElementById('a');
var d = document.getElementById('d')
if (a.contains(d)) {
    alert('d is a child of a');
}
if (d.contains(a)) {
    alert('a is a child of d');
}