Learn how to add class to parent li if it has child ul inside, using jQuery, without the need to check if the ul exists. You can add class to each level.

Learn how and when to use jQuery $(this) selector, together with event functions such as click, hover, focus, blur and also when you want to refer on multiple items of the same type.

Here is how you can create a jQuery dropdown menu using slideToggle or fadeToggle animation, when you click or hover on a parent list item.