Base Classes and Derived Classes

Base Classes 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.