Classes

This lab discusses:

1. What is a class
2. Class definitions
3. Access control
4. Constructor
5. Member function definitions
6. How to instantiate an object of a class
7. How to call member functions

Class Definition

class Class_name
{
public:
  constructor declaration
  member function declarations
private:
  data members
};

Member Function Definitions

output Class_name::memberfunName(input parameters)
{
  body of the function
}

Example: Point.cpp (Point class)

Exercise

Write a Rectangle class using the Point class and test it using a main program (i.e., in a main() function).

A rectangle is specified by two corner points. The sides of the rectangle are parallel to the coordinate axes.

Consider the following design description of the Rectangle class:

Knows:

• its bottom-left corner point
• its top-right corner point

Can do:

• Initialization
• Return its bottom-left corner point
• Return its top-right corner point
• Return its circumference
• Return its area
• Move by dx and dy