JSFiddle - React, Tailwind, and code Playground

HTML

<ul class="tabs">
    <li><a class="active" href='#'>One</a></li>
    <li><a href='#'>Two</a></li>
    <li><a href='#'>Three</a></li>
</ul>

JavaScript

$("ul.tabs li a").on("click",function() {
        var li = $(this).parent();
        alert(li.index());
});