C++ program to implement run time polymorphism.

Run time polymorphism is a great facility provided by Object Oriented Programming. It essentially requires inheritance. Also in this concept base class pointer is used to hold address of base class object as well as address of derived class object. To successfully implement the concept of polymorphism it is necessary that function prototyping in base as well as derived class must be identical with only one exception that base class function must be declared as virtual function.
In such situation when base class pointer hold address of base class object then it invoke base class function and when base pointer hold address of derived class then it invokes the derived class function.
The same concept is used in below program.
Please include iostream.h, conio.h and stdio.h header files before declaration of class publication.
//PROGRAM TO IMPLEMENT RUN TIME POLYMORPHISM
#include
#include
#include
class publication
{
private:
char title[20];
float price;
public:
virtual void getdata(void)
{
cout<<"Enter title and price\n";
gets(title);
cin>>price;
}
virtual void putdata(void)
{
cout<<"\nTitle is "< cout<<"\nPrice is "< }
};
class book:public publication
{
private:
int pagecount;
public:
void getdata(void)
{
cout<<"\nEnter page count of book\n";
cin>>pagecount;
}
void putdata(void)
{
cout<<"\nPage count is "< }
};
class tape:public publication
{
private:
int playtime;
public:
void getdata(void)
{
cout<<"\nEnter the play time of tape\n";
cin>>playtime;
}
void putdata(void)
{
cout<<"\nPlay time of tape is "< }
};
void main(void)
{
class publication *arr[3];
class publication p;
class book b;
class tape t;
clrscr();
arr[0]=&p;
cout<<"\nWe are collectiong comman details of publication\n";
arr[0]->getdata();
arr[1]=&b;
cout<<"\nNow we are collecting book data\n";
arr[1]->getdata();
arr[2]=&t;
cout<<"\nNow we are collecting tape data\n";
arr[2]->getdata();
clrscr();
cout<<"\nBOOK DETAILS ARE AS FOLLOWS\n";
arr[0]->putdata();
arr[1]->putdata();
cout<<"\n\n**********************************************************\n";
cout<<"\nTAPE DETAILS ARE AS FOLLOWS\n";
arr[0]->putdata();
arr[2]->putdata();
cout<<"\n\n**********************************************************\n";
getch();
}