Abstract Class

Abstract class is one that which not used to create object. An abstract class is designed only to act as base class and it is inherited by other class.

It is designed concept in the program development and provide a base upon which other classes may be built.

Remember that a class containing pure virtual function can not be used to declare the any objects of it own. As stated earlier such classes are called as abstract base class.

#include<conio.h>
#include<iostream.h>
class A
{
public:
virtual void getdata( ) {   }
virtual void putdata( )=0;
};
class B : public A
{
public:
void getdata( )
{
cout<<"\n\t This is B class getdata( )";
}
void putdata( )
{
cout<<"\n\t This is B class putdata( )";
}
};
void main( )
{
clrscr( );
A a;
B b;
b.getdata( );
b.putdata( );
getch( );
}