Software & Finance





C++ - Inheritance





Inheritance means classes can be derived from another class called base class. Derived classes will have all the features of the base class and it will have access to base class protected and public members. Derived classes will not have access to private members of the base class.

 

We know C++, C# and Java supportes inheritance. But there are differences in the inheritance implementation between C++, C# and Java Inheritance. In C++, you need to use the virutal keyword in both base and derived classes. In C#, you need to use virual keyword in base case and override keyword in derived classes.

 

In Java you do not need to use any keyword like virtual or override since by default all non static functions are considered as virual. You have to make it either private or use final keyword to remove the default virtual feature in each function in the Java classes.

 

When writing derived classes C++ and C# uses ":" between derived class and base class. Java uses extends keyword instead of :


In this sample, Shape is the base class. Triangle and Circle are the derived classes derived from the base class Shape. It is called inheritance.

 

Useful links:

Inheritance in C++

Inheritance in C#

Inheritance in Java

Source Code


 

class Shape

{

public:

 

    Shape()

    {

        std::cout << "Shape\n";

    }

 

    virtual void draw() { }

    virtual void display() { }

 

};

 

class Circle : public Shape

{

    int r;

public:

    Circle()

    {

        std::cout << "Circle\n\n";

    }

    virtual void draw() {}

    virtual void display() { }

 

};

 

class Triangle : public Shape

{

    int a,b,c;

 

public:

    Triangle()

    {

        std::cout << "Triangle\n\n";

    }

 

    virtual void draw() {}

    virtual void display() { }

};