Virtual Function in C++

Virtual Function in C++

 

Virtual Function is one of the advances features of OOPs . A virtual function (also known as virtual methods) is a member function that is declared within a base class and is re-defined (overridden) by a derived class.

Polymorphism refers to the property by which objects belonging to different classes are able to
respond to the same message, but different forms. An essential requirement of polymorphism is therefore the ability to refer to objects without any regard to their classes.
When we use the same function name in both the base and derived classes, the function in the bas
class is declared as virtual using the keyword virtual preceding its normal declaration.

CODE :

#include <iostream>
using namespace std;

class Base {
   public:
    virtual void print() {
        cout << "Base Function" << endl;
    }
};

class Derived : public Base {
   public:
    void print() override {
        cout << "Derived Function" << endl;
    }
};

int main() {
    Derived derived1;

    // pointer of Base type that points to derived1
    Base* base1 = &derived1;

    // calls member function of Derived class
    base1->print();

    return 0;
}

 

OUTPUT :

Derived Function