jquery show/hide with toggleable icons

toggle.js

//usage -- 
//<i class="show-hide" data-elem="#hidden-content"></i>  
//<div id="my-content" class="hidden">I'm hidden until the icon is clicked</div>

$(document).ready(function() {
        $('.show-hide').on('click', function(e) {
            e.preventDefault();
            var elem = $(this).attr('data-elem');
            $(elem).toggleClass('hidden');
            $(this).toggleClass('glyphicon-menu-down');
            $(this).toggleClass('glyphicon-menu-up');
        });
    });