CPP

polymorphism c++ virtual

// C++ program to demonstrate how we will calculate
// area of shapes without virtual function
#include <iostream>
using namespace std;
 
// Base class
class Shape {
public:
    // parameterized constructor
    Shape(int l, int w)
    {
        length = l;
        width = w;
    }
    int get_Area()
    {
        cout << "This is call to parent class area
";
        // Returning 1 in user-defined function means true
        return 1;
    }
 
protected:
    int length, width;
};
 
// Derived class
class Square : public Shape {
public:
    Square(int l = 0, int w = 0)
        : Shape(l, w)
    {
    } // declaring and initializing derived class
    // constructor
    int get_Area()
    {
        cout << "Square area: " << length * width << '
';
        return (length * width);
    }
};
// Derived class
class Rectangle : public Shape {
public:
    Rectangle(int l = 0, int w = 0)
        : Shape(l, w)
    {
    } // declaring and initializing derived class
    // constructor
    int get_Area()
    {
        cout << "Rectangle area: " << length * width
             << '
';
        return (length * width);
    }
};
 
int main()
{
    Shape* s;
 
    // Making object of child class Square
    Square sq(5, 5);
 
    // Making object of child class Rectangle
    Rectangle rec(4, 5);
    s = &sq; // reference variable
    s->get_Area();
    s = &rec; // reference variable
    s->get_Area();
 
    return 0; // too tell the program executed
    // successfully
}