Extending a class using an extension

Just as you saw with structs, classes can be re-opened using the extension keyword to add methods and computed properties. Add a fullName computed property to Student:

extension Student {

var fullName: String {

return "(firstName) (lastName)"

}

}

Functionality can also be added to classes using derivation. You can even add new stored properties to derived classes. You will explore this technique in detail in the next chapter.