#hpsc asst proff

Question

if a class will serve as a base class , more often the base class data members are:-

a) private

b) public

c) protected

d) polymorphic

Comments

Option A should be correct.

 Base class data members are one of public, protected, or private depending upon the access-specifier used in base-class.

If the access-specifier is not used , then it is private by default.

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according to answer key its public.....can use please give some refernce for it ?

Answer 1

A base class is accessed by a derived class in one of the following ways:

1. Class X: public B

2. Class X: Private B

3. Class X: protected B

Member of a base class are always private by default. However they can made public  by using access specifier public.

If the base class is derived as public,then its data members can be accessed  directly by derived class members.

With private inheritance the public and protected members of base class becomes private members of derived class. They cannot be accessed directly by an object of derived class. 

With protected inheritance, The data members can be accessed by member functions of derived class and its friend function.

There is no term like most often, the members are private by default. And it is programmer's choice how she/he want to access them in the derived class.

Reference: 1. Page 346-351 , Book : Programming with C++, B.L. Juneja andAmita Seth.  (new Age International Publisher)

2. Page 405, Book: The C++ programming Language, Third Edition, Bjarne Stroustrup. 

3. https://en.wikipedia.org/wiki/C%2B%2B_classes