Constructors and Destructors in Derived Classes

Constructors and Destructors in Derived Classes

• In the inheritance, First the Base class constructor is called, and after that the Derived class constructor is called. Because the Derived class inherits from the Base class, both the Base class and Derived class constructors will be called when a Derived class object is created.

• When the main function is finished running, the object's destructor will get called first, and after that the Base class destructor will be called.

• Following code illustrates this execution order

#include <iostream>

using namespace std;

class Base

{

public:

Base()

{

   cout << "Base constructor" << endl;

}

~Base()

{

   cout << "Base destructor" << endl;

}

};

class Derived:public Base

{

public:

Derived()

{

   cout<<"Derived constructor" << endl;

}

~Derived ()

{

   cout<<"Derived destructor" << endl;

}

};

void main()

{

   Derived obj;

}

Output

Base constructor

Derived constructor

Derived destructor

Base destructor

Review Questions

1. Explain the order of execution of constructor and destructor with the help of suitable example.

2. Write a program to illustrate how constructors are implemented when the classes are inherited?