So far, you have only used classes created by Apple. Now you get to write your own class. Remember that a class describes objects in two ways:
methods (both instance methods and class methods) implemented by the class
instance variables within each instance of the class
You’re going to write a Person class, similar to the struct Person you wrote in Chapter 10. Your class will be defined in two files: Person.h and Person.m. Person.h, known as the header or interface file, will contain the declarations of instance variables and methods. Person.m is known as the implementation file. This is where you write out the steps for, or implement, each method.
Create a new project: a Foundation Command Line Tool named BMITime.
To create a ...