Pure virtual function in c++

Hello friends, in this post today, we learn about what is pure virtual  function in c++ and how to use pure virtual function in c++. so lets start...

Pure virtual function in c++

Pure virtual function:-

A pure virtual function is a function which has its body set to 0 i.e., the pure virtual function does not have any body.

A pure virtual function means ‘do nothing’ function.

A function declared in a way:

Syntax:-virtual void display() = 0; 

is known as pure virtual function. Here = 0 does not mean that function show is equal to 0. It simply means that the virtual function show has no body. 

The pure virtual function act as an interface and any class which inherits the class in which pure virtual function is present, has to provide the implementation for the function show.

We can say empty function. A pure virtual function has no definition relative to the base class. Programmers have to redefine pure virtual function in derived class, because it has no definition in base class.

A class containing pure virtual function cannot be used to create any direct objects of its own. This type of class is also called as abstract class.

An abstract class is a class whose objects cannot be created. but pointers and references of an abstract class can be created.

Example:-

#include <iostream>

using namespace std;

class A

{

  public:

  void virtual Display()=0;

};

class B:public A

{

  public :

  void Display()

   {

    cout<<"Demo of virtual Function"<<endl;

   }

};

int main()

{ 

  A *ptr=new B;     

  ptr->Display();   

  return 0;

}

Output:-

Demo of virtual Function

I hope that whatever information I have given in this post today, you have liked it and you have understood it.so keep learning and wait for the next post that will help you to increase your knowledge with the something new information.

Thank you so much for reading. And take care about yourself and your family.