JSFiddle - React, Tailwind, and code Playground

by David Thomas

HTML

<ul>
    <li class="cls">one</li>
    <li class="cls active">two</li>
    <li class="cls">here</li>
    <li class="cls">after</li>
</ul>

CSS

.red {
    color: #f00;
}

JavaScript

var c = $('.cls'),
    active = c.filter('.active');

active.addClass('red');