JSFiddle - React, Tailwind, and code Playground

HTML

<div class=container>
</div>

JavaScript

var container=$("div.container").get(0),
    htmlA="<div class=children>A</div>",
    htmlB="<div class=children>B</div>";

// jquery object

alert( $(container).append(htmlA) ); // outputs "[object Object]"

// html dom element

alert( $(container).append(htmlB).get(0) ); // outputs "[object HTMLDivElement]"