JSFiddle - React, Tailwind, and code Playground

by fest1val

HTML

<div class="some">1</div>
<div class="some">2</div>
<div class="some">3</div>
<div class="some">4</div>
<div class="some">5</div>
<div class="some">6</div>

JavaScript

function insertAfter(elem, refElem) {
  return refElem.parentNode.insertBefore(elem, refElem.nextSibling);
}

var refElem = document.getElementsByClassName('some')[2]; //начинается с 0

var elem = document.createElement('div');
elem.innerHTML = '<b>Нужное содержимое</b>';


insertAfter(elem, refElem);