JSFiddle - React, Tailwind, and code Playground

HTML

<ul class='myList'>
<li class='on'>One</li>
<li>Two</li>
<li>Three</li>
<li>Four</li>
<li>Five</li>
<li>Six</li>
<li>Seven</li>
</ul>

<input type='button' class='next' value='Next'>

CSS

.on {
    background-color: red;
}

JavaScript

$('.next').click(function(){
    var current = $('ul.myList').find('li.on');
    current.removeClass('on');
    current.next().addClass('on');
});