programming-for-dummies

Real-Life Programming Examples 249
Real-Life Programming Examples
To fully understand object-oriented programming, you need to see how to
use OOP in a real programming language. Basically, the steps to using OOP
involve
✦ Defining an object with a class file
✦ Creating an object based on a class
✦ Using subprograms (methods) in an object
✦ Inheriting an object
✦ Using polymorphism to rewrite an inherited subprogram
Book II
Chapter 7
Although the following examples use C++, don’t worry about the particular
syntax of each programming language example. Because every programming
language uses different syntax and commands, focus on understanding the
principles behind creating and using objects.
Defining an object with a class
To create an object, you must first create a class, stored in a separate file
that defines
Breaking a
Large Program
into Objects
✦ The data (properties) the object contains
✦ The subprograms (methods) the object uses to manipulate its data
At the simplest level, a C++ class consists of the class keyword along with a
descriptive name for your class, such as
class ClassName
{
};
So if you wanted to name your class animal, your class would now look like
this:
class animal
{
};
Next, you need to define the public data (properties) and subprograms
(methods) by using the public keyword. Then you must define the private
data and subprograms by using the private keyword, such as
class animal
{