C++ Program – Create a class Shape with two private data members.

C++ Program – Create a class Shape with two private data members.

a. Define constructor to initialize the data members.

b.   Define a virtual function two calculate area of the shape.

c.     Create derive classes rectangle and circle and implement area function.

Create objects and show the implementation of defined operation.

/*19. Create a class Shape with two private data members.
      a. Define constructor to initialize the data members.
      b. Define a virtual function to calculate the area of the shape.
      c. Create derive classes rectangle and circle and implement area
	function. */

 #include<iostream.h>
 #include<conio.h>
 #include<string.h>
 #define pi 3.141
 class Shape
 {
  private:
    char s_name[15];
    float s_area;
  public:
    Shape()
    {
     strcpy(s_name," ");
     s_area=0.0;
     }
    void init(float a)
    {
     s_area=a;
     }
    virtual void input()              //virtual function
    {
     cout<<endl<<"Enter Shape Name="<<endl;
     cin>>s_name;
     }
    void display()
    {
     cout<<endl<<"*************************"<<endl<<endl;
     cout<<"Shape name="<<s_name<<endl;
     cout<<s_name <<" "<<"Area="<<s_area<<endl;
     cout<<endl<<"*************************"<<endl<<endl;
     }
 };
 class Rectangle:public Shape
 {
  private:
   float length,width,r_area;
  public:
   Rectangle()
   {
    length=width=r_area=0.0;
    }
   void input()
   {
    Shape::input();
    cout<<"Enter length="<<endl;
    cin>>length;
    cout<<"Enter width="<<endl;
    cin>>width;
    r_area=length*width;
    Shape::init(r_area);
    }
   void display()
   {
    Shape::display();
    }
 };
 class Circle:public Shape
 {
  private:
   float radious,c_area;
  public:
   Circle()
   {
    radious=c_area=0.0;
    }
   void input()
   {
    Shape::input();
    cout<<"Enter radious="<<endl;
    cin>>radious;
    c_area=pi*radious*radious;
    Shape::init(c_area);
    }
   void display()
   {
    Shape::display();
    }
 };
 void main()
 {
  clrscr();
  Rectangle r;
  Circle c;
  cout<<">>>>> Rectangle <<<<<"<<endl<<endl;
  r.input();
  r.display();
  cout<<">>>>> Circle <<<<<"<<endl<<endl;
  c.input();
  c.display();
  getch();
  }