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="#">Dropdown link2</a></li>
        </ul>
    </li>
</ul>

CSS

#menu1 li a.active{
    font-weight:bold;
}

JavaScript

$('#menu1 li a').click(function(e) {
    if($('a').hasClass('dropdown-class-name active')=="false"){$('a').removeClass('dropdown-class-name active');}
    $(this).addClass('dropdown-class-name active');
});