JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.0.3/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.0.3/css/bootstrap.min.css">
<ul>
    <li class="dropdown"> <a href="#" class="dropdown-toggle" data-toggle="dropdown">Link</a>

        <ul class="dropdown-menu">
            <li><a href="#">Item</a>

            </li>
            <li><a href="#">Item</a>

            </li>
            <li><a href="#">Item</a>

            </li>
        </ul>
    </li>
</ul>

JavaScript

$('.dropdown-toggle').hover(function () {
    $(this).next('.dropdown-menu').fadeToggle(500);
});