D. Fraction and Address Book Examples
Here, for your reference purposes, are the complete interface and implementation files for the fractions you worked with extensively in Part I, “The Objective-C Language,” and the address book example you worked with throughout Part II, “The Foundation Framework.” This includes the definitions for the
AddressBook classes. You should implement these classes on your system. Also, extend the class definitions to make them more practical and powerful (for example, see exercises 2–7 at the end of Chapter 15, “Numbers, Strings, and Collections”). This is an excellent way for you to learn the language and become familiar with building programs, working with classes and objects, and (in ...