Page 211 - DCAP404 _Object Oriented Programming

Object-oriented Programming

Notes Self Assessment

Fill in the blanks:
15. The destruction of the base class object named unicycle is no problem, its destructor is
executed and the ………………….. is gone.

16. In a multi-level inheritance, the …………………… will be executed in the order of
inheritance.

9.8 Making a Private Member Inheritable

The members of base class which are inherited by the derived class and their accessibility is
determined by visibility modes. Visibility modes are:
1. Private: When a base class is privately inherited by a derived class, ‘public members’ of
the base class become private members of the derived class and therefore the public
members of the base class can be accessed by its own objects using the dot operator. The
result is that we have no member of base class that is accessible to the objects of the
derived class.

2. Public: On the other hand, when the base class is publicly inherited, ‘public members’ of
the base class become ‘public members’ of derived class and therefore they are accessible
to the objects of the derived class.
3. Protected: C++ provides a third visibility modifier, protected, which serve a little purpose
in the inheritance. A member declared as protected is accessible by the member functions
within its class and any class immediately derived from it. It cannot be accessed by functions
outside these two classes.

The below mentioned table summarizes how the visibility of members undergo modifications
when they are inherited.
Table 9.2: Execution of base Class Constructors

Base Class Visibility Derived Class Visibility
Public Private Protected
Private X X X
Public Public Private Protected
Protected Protected Private Protected

The private and protected members of a class can be accessed by:
1. A function i.e. friend of a class.

2. A member function of a class that is the friend of the class.
3. A member function of a derived class.

Self Assessment

Fill in the blanks:
17. A member declared as ……………………. is accessible by the member functions within its
class and any class immediately derived from it.

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