JSFiddle - React, Tailwind, and code Playground

HTML

<div>Hello,
<div class="el1">world!</div>
</div>

JavaScript

var $element1 = $(".el1").eq(0);
var $element2 = $(".el1").eq(0);

$element1.append($element2);

// After this we expect in results: "Hello, world!" ... or do we?