JSFiddle - React, Tailwind, and code Playground
HTML
<ul id="menu" class="sidebar">
<li> <a href="#" class="clickme">Menu</a>
<ul id="menu1">
<li><a class="dropdown-class-name" href="#">Dropdown link1</a></li>
<li><a class="dropdown-class-name" href="http://jsfiddle.net/hnxhcbgw/">Dropdown link2</a></li>
</ul>
</li>
</ul>
CSS
#menu1 li a.active{
font-weight:bold;
}
JavaScript
var localURL = '[href="'+window.location.href+'"]'
$('#menu1 li a'+localURL).click(function(e) {
$('a').removeClass('dropdown-class-name active');
$(this).addClass('dropdown-class-name active');
});