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]"