JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.7.0/themes/base/jquery-ui.css">
<button id="button">Click me</button>

<div id="tabs">
    <ul>
        <li><a href="#tabs-1">Nunc tincidunt</a></li>
        <li><a href="#tabs-2">Proin dolor</a></li>
        <li><a href="#tabs-3">Aenean lacinia</a></li>
    </ul>
    <div id="tabs-1">
        Tab 1. Index 0
    </div>
    <div id="tabs-2">
        Tab 2. Index 1
    </div>
    <div id="tabs-3">
        Tab 3. Index 2
    </div>
</div>

JavaScript

$(function() {

    $("#tabs").tabs();

    $("#button").click(function() {
        var current_index = $("#tabs").tabs("option","selected");
        alert("The index of the current tab is " + current_index);
    });
});