This simple example consists of an overview of the syntax of Polymorphism and practical use of Virtual Destructor in C++

polymorphism.cpp

// This source code written by Roland Ihasz 
#include <iostream>

using namespace std;
// base class
class GPSCoordinates {
protected:
    double latitude, longitude;
    string name;
public:
    GPSCoordinates(double la, double lo, string n) {
        latitude = la;
        longitude = lo;
        name = n;
    }
    virtual ~GPSCoordinates(){      // Virtual Destructor // Tidying Up...
        cout<<">> GPSCoordinates-Base Destructor called" << endl;
    }
    void display() {
        cout << name << " GPS Coordinates in Decimal Degrees (WGS84)"
        << endl << "Latitude: " << latitude
        << ", Longitude: " << longitude << endl;
    }
};
// derive class
class Hawaii : public GPSCoordinates { // constructor
public:
    Hawaii (double la, double lo, string n) :
    GPSCoordinates(la,lo,n) {}
    
    virtual ~Hawaii(){      // Virtual Destructor // Tidying Up...
        cout<<">> Hawaii-Derived destructor called" << endl;
    }
};

class Dublin : public GPSCoordinates {
public:
    Dublin(double latitude, double longitude, string name) :
    GPSCoordinates(latitude, longitude, name) {}
    
    virtual ~Dublin(){  // Virtual Destructor // Tidying Up...
        cout<<">> Dublin-Derived destructor called" << endl;
    }
};

int main()
{
    Hawaii loc1(21.3069400, -157.8583300, "Hawaii");
    Dublin loc2(53.3439900, -6.2671900, "Dublin");
    loc1.display();
    loc2.display();
    cout << endl << "Tidying Up..." << endl;
    return 0;
}