Throughout the first four chapters of this book, we have been using the .addClass() and .removeClass() methods to demonstrate how we can change the appearance of elements on a page. Effectively, what these two methods are doing is manipulating the class attribute (or, in DOM scripting parlance, the className property). The .addClass() method creates or adds to the attribute, while .removeClass() deletes or shortens it. Add to these the .toggleClass() method, which alternates between adding and removing a class, and we have an efficient and robust way of handling classes.

Nevertheless, the class attribute is only one of several attributes that we may need to access or change: for example, id and rel and href. For these attributes, jQuery has the .attr() and .removeAttr() methods. We could even use .attr() and .removeAttr() instead of their respective .class() methods, if we wanted to do it the hard way (but we don’t).