What is a virtual destructor?

What is a virtual destructor?

* Virtual destructor ensures that the object destruction happens from the most derived class towards the base class.
* Significant in scenarios where a derived class object is assigned to a base class pointer.

EXAMPLE: Demonstrate the object destruction sequence.

#include

using namespace std;

class Base {

public:
Base() {
cout << "Base class constructor ..." << endl;
}
~Base() {
cout << "Base class destructor ..." << endl;
}
};

class Derived : public Base {

public:
Derived() {
cout << "Derived class constructor ..." << endl;
}
~Derived() {
cout << "Derived class destructor ..." << endl;
}
};

void main()
{
Base* base;
base = new Derived();
delete base;
}

OUTPUT:
Base class constructor ...
Derived class constructor ...
Base class destructor ...



EXAMPLE: Demonstrate the object destruction sequence using virtual destructor


#include

using namespace std;

class Base {

public:
Base() {
cout << "Base class constructor ..." << endl;
}
virtual ~Base() {
cout << "Base class destructor ..." << endl;
}
};

class Derived : public Base {

public:
Derived() {
cout << "Derived class constructor ..." << endl;
}
~Derived() {
cout << "Derived class destructor ..." << endl;
}
};

void main()
{
Base* base;
base = new Derived();
delete base;
}

OUTPUT:
Base class constructor ...
Derived class constructor ...
Derived class destructor ...
Base class destructor ...