LAB 3 – Introduction to Classes (INDIVIDUAL WORK)

Implementing a Class for Circles

A circle can be described by its radius and the coordinates of its center. The circle can be changed by modifying any or all of these three values. We can also calculate the area of the circle.

The Circle class will contain three data items: the radius of the circle and the x and y coordinates of the center. The Circle class will also define the functions (or methods) for altering a circle, for displaying its values,and for calculating its area.

Complete the Circle class and test program shown below.

Homework: add a function to return the circumference. Add a test to the function in main.

#include <iostream>
using namespace std;

class Circle
{
   public:
      // Default Constructor
      Circle();

      // Constructor
      Circle( const int centerX,
              const int centerY,
              const int radius );

      // Get the radius
      int get_radius();

      // Set the radius of the circle
      void set_radius( const int aRadius );

      // Get the x-coordinate of the center
      int get_centerX();

      // Set the x-coordinate of the center
      void set_centerX( const int aCoordinate );

      // Get the y-coordinate of the center
      int get_centerY();

      // Set the y-coordinate of the center
      void set_centerY( const int aCoordinate );

      // Calculate the area of the circle
      double area();

      // Print the circle
      void print();

   private:
      int myCenterX;
      int myCenterY;
      int myRadius;
};

// Default Constructor
Circle::Circle()
{
 // add code here
}

 
// Constructor
Circle::Circle( const int centerX,
                const int centerY,
                const int radius )
{
  // add code here
}


// Get the radius of the circle
int Circle::get_radius()

{
   // Add Code Here
}

 
// Set the radius of the circle
void Circle::set_radius( const int aRadius )
{
   // Add Code Here
}

// Get the x-coordinate of the center
int Circle::get_centerX()
{
   // Add Code Here
}

// Set the x-coordinate of the center
void Circle::set_centerX( const int aCoordinate )
{
   // Add Code Here
}

 
// Get the y-coordinate of the center
int Circle::get_centerY()
{
   // Add Code Here
}

// Set the y-coordinate of the center
void Circle::set_centerY( const int aCoordinate )
{
   // Add Code Here
}

// Calculate the area of the circle
double Circle::area()
{
   // Add Code Here
}

 
// Print the circle
void Circle::print()
{
   cout << "Center: (" << myCenterX << ", " << myCenterY << ") "
        << "Radius: " << myRadius << endl;
}

 
int main()
{
   // Test program for the Circle class

   // First test the constructors
   cout << "Testing Constructors" << endl;
   Circle firstCircle;
   Circle secondCircle(1, 2, 3);

   cout << "  Using Default Constructor: " << endl;
   cout << "    ";
   firstCircle.print();

   cout << "  Using Constructor with Parameters 1, 2, 3: " << endl;
   cout << "    ";
   secondCircle.print();
   cout << endl;


   cout << "Accessing contents of first circle using get functions: " << endl;
   cout << "    First circle radius is " << firstCircle.get_radius() << endl; 
   cout << "    First circle center is (" << firstCircle.get_centerX() << 
           ", " << firstCircle.get_centerY() << ")" << endl; 
   cout << endl;

   cout << "Testing set functions: " << endl;
   cout << "    Moving the first circle to the position (5, 6): " << endl;
   firstCircle.set_centerX(5);
   firstCircle.set_centerY(6);
   cout << "     First Circle is: ";
   firstCircle.print();
   cout << endl;

   cout << "    Changing the radius of second circle to 10: " << endl;
   secondCircle.set_radius( 10 );
   cout << "     Second Circle is: ";
   secondCircle.print();
   cout << endl;

   cout << "Testing the area function" << endl;
   cout << "  First circle area is: " << firstCircle.area() << endl;
   cout << "  Second circle area is: " << secondCircle.area() << endl;
   cout << endl;
}