Exercise 6-1. A visual representation of a class, its member fields and methods, and its place in the hierarchy is called a class diagram. There are several accepted methods for drawing a class diagram, but we won't hold you to any of those right now. For this exercise, simply draw a class diagram for a class named vehicle, listing some member fields and methods that you think that class should have. Then add to your diagram the derived classes car, boat, and plane, and list their fields and methods (remember that all derived classes inherit the fields and methods of their parent class).
Exercise 6-2. You've defined a class as a diagram; now try defining one in code. Define a class Book, in which a book has a title, author, and ISBN, and the book can be read or shelved. You don't need to fill in the code for any methods you include; simply include a comment in the body, like we did for the Dog class earlier in the chapter.