JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>Item 1</li>
    <li>Item 2</li>
    <li>Item 3</li>
    <li>Item 4</li>
    <li>Item 5</li>
</ul>

JavaScript

var $li = $("ul > li");
$li.each(function (i) {
    $(this).text('Item ' + ($li.length - i));
});