Javascript onClick for mobile devices

Question

I am working on a submenu for a nav that I need to be accessible for mobile and tablet devices. I am aware that using onClick="return true" will do the trick, however, I also need my list item to close when the user clicks on the list item. Basically I need it to toggle the submenu. If I add this simple line of Javascript, it will work but the submenu will always remain open. How can I get it to close/toggle the submenu?

HTML:
        <nav>
            <ul>
                <li class="active"><a href="#">Menu 1</a></li>
                <li><a href="#">Menu 2</a></li>
                <li><a href="#">Menu 3</a></li>
                <li class="bg"><a class="dropdown" href="#">Menu 4</a>
                    <ul>
                        <li><a href="#">Sub 1</a></li>
                        <li><a href="#">Sub 2</a></li>
                    </ul>
                </li>
            </ul>
        </nav>

Javascript:
$('nav li.bg').on('click', function(){
  return true;
}

Answer 1

You can use touchstart event which fires on mobile browsers.

$('nav li.bg').on('click touchstart', function(){
    return true;
});

More touch based events