Base and Derived Classes

Base and Derived Classes

• The class from which the data members and member functions are used by another class is called the base class.

• The class which uses the properties of base class and at the same time can add its own properties is called derived class.

•  There are three types of access specifier or qualifier using which the members of the class are accessed by the other class ‒

1. Private

2. Public

3. Protected

•  If a base class has private members then those members are not accessible to derived class.

•  Protected members are public to derived classes but private to rest of the program.

•  Public members are accessible to all.

• The derived class can inherit base class publicly or privately. The notation used for inheritance is :

For example ‒

class d1:public b1

class d2:private b2

The first line indicates that there are two classes d1 and b1. It means "the derived class d1 inherits the base class b1 publicly".

The second line indicates that there are two classes d2 and b2. It means "the derived class d2 inherits the base class b2 privately."

•  The base class and derived class can generate their own objects. These objects differ from each other.

Review Question

1. Explain the terms base class and derived class.