Pure Virtual Function Program in C++

In this article we will learn how to implement a pure virtual function program in C++. A C++ program is provided to illustrate the concept of pure virtual function and calculate the area of different shapes by using abstract class. Program is as follows:

#include <iostream>
using namespace std;
class Shape
{
	public:
		virtual void area() = 0;
};
class Rectangle : public Shape
{
	private:
		int l;
		int b;
	public:
		Rectangle(int x, int y)
		{
			l = x;
			b = y;
		}
		void area()
		{
			cout<<"Area of rectangle is: "<<(l*b)<<endl;
		}
};
class Circle : public Shape
{
	private:
		int r;
	public:
		Circle(int x)
		{
			r = x;
		}
		void area()
		{
			cout<<"Area of circle is: "<<(3.142*r*r)<<endl;
		}
};
int main()
{
	Shape *s;
	s = new Rectangle(10, 20);
	s->area();
	s = new Circle(2);
	s->area();
	return 0;
}

Output for the above program is as follows:

Area of rectangle is: 200
Area of circle is: 12.568

Suryateja Pericherla

Suryateja Pericherla, at present is a Research Scholar (full-time Ph.D.) in the Dept. of Computer Science & Systems Engineering at Andhra University, Visakhapatnam. Previously worked as an Associate Professor in the Dept. of CSE at Vishnu Institute of Technology, India.

He has 11+ years of teaching experience and is an individual researcher whose research interests are Cloud Computing, Internet of Things, Computer Security, Network Security and Blockchain.

He is a member of professional societies like IEEE, ACM, CSI and ISCA. He published several research papers which are indexed by SCIE, WoS, Scopus, Springer and others.