JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <p id="foo">
        <span></span>
    </p>
</div>

<div id="queryS"></div>
<div id="jquery"></div>

JavaScript

var foo = document.getElementById("foo");

var jquery = $(foo).find("div span").length;
var queryS = foo.querySelectorAll('div span').length;

$("#queryS").html( "QuerySelector: " + queryS + " Element found!");
$("#jquery").html("jQuery: " + jquery + " Elements found!");