JSFiddle - React, Tailwind, and code Playground
by Nymos
HTML
<div id="side">
<h2 class="1">1</h2>
<h2 class="2">2</h2>
<ul>
<li><a class="3" href="#">3</a></li>
<li><a class="4" href="#">4</a></li>
</ul>
</div>
JavaScript
$(document).ready(function(){
$('#side a').on('click', function(){
var index = $('#side a').index(this);
// alert(index);
alert($('#side h2').eq(index).html());
});
});