README.md

Detect window size with Javascript

detect-window-size.js

jQuery(document).ready(function($){
  
  var $window = $(window),
        $menu = $('div.menu');
	
	function checkWindowSize() {
		var width = $window.width();
		if ( width < 824 ) {
			return $menu.addClass('nav-mobile');
		}
		$menu.removeClass('nav-mobile');
	}
	
	$window
        .resize(checkWindowSize)
        .trigger('checkWindowSize');
		
	checkWindowSize();
	
	/* prepend menu icon */
	$('div.menu').prepend('<div id="menu-icon">Menu</div>');
	
	
	/* toggle nav */
	$("#menu-icon").on("click", function(){
		$("div.menu > ul").slideToggle();
		$(this).toggleClass("active");
	});

});