JSFiddle - React, Tailwind, and code Playground

HTML

<div id="div1">STUFF ONE</div>
<br/>
<div id="div2">STUFF TWO</div>

CSS

.replaced{color:red}

JavaScript

div1 = $('#div1');
div2 = $('#div2');

tdiv1 = div1.clone();
tdiv2 = div2.clone();

if(!div2.is(':empty')){
    div1.replaceWith(tdiv2);
    div2.replaceWith(tdiv1);
    
    tdiv1.addClass("replaced");
}