JSFiddle - React, Tailwind, and code Playground

HTML

<div id="classe">
    <div>
      <div></div>
    </div>
    <div></div>
</div>

JavaScript

/*
var minhaClasse = document.getElementById('classe');
alert(minhaClasse.children.length);
*/

var teste = $("#classe").children().length;
alert(teste);