JSFiddle - React, Tailwind, and code Playground

HTML

<section class="class">
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin nisi ligula, dapibus a volutpat sit amet, mattis et dui. Nunc porttitor accumsan orci id luctus. Phasellus ipsum metus, tincidunt non rhoncus id, dictum a lectus. Nam sed ipsum a lacus sodales eleifend. Vestibulum lorem felis, rhoncus elementum vestibulum eget, dictum ut velit. Nullam venenatis, elit in suscipit imperdiet, orci purus posuere mauris, quis adipiscing ipsum urna ac quam. 
</section>

JavaScript

var someVar = $('.class');

$.fn.runFunction = function() {
    someVar.css('color', 'red' );
}

someVar.runFunction();