C++ Programming - Objects and Classes - Discussion

A constructor can be private and we can create an object for that class using the friend class.

A constructor can be Private. For example: singleton mechanism.

For providing data security to make data and function must be either public and private in a single class private and protected acts as same, So option B is correct.

I agree, thanks @Soumya Raj.

Because the caller of constructor is compiler, and compiler is 3rd party so it constructor should not be private.

A private constructor is a special instance constructor. It is generally used in classes that contain static members only. So (D) cannot be the correct answer.

If a Constructor is Private then the object created in the main function cannot be initialized as private members of a class cannot be called by the main() function.

So, Constructor cannot be Private.

And sorry for offending @ Jay. But explain me how a Private Constructor is useful to construct an Object. How come you can create an Object in a Class without creating the actual instance of that Class.

I know that Constructor cannot be private. But how?

The answer (B) is incorrect. Because any data and function.

Within the class can be public, protected or private, they aren't restricted only to be private or public. The access specifier 'protected' isn't mentioned in option (B). Hence the option (B) is either partially correct or incorrect.

Whereas option (D) is correct. Because it isn't possible to declare constructor as either private or protected. It must be declared as public. Hence the statement of option (D) is totally correct.

Here the correct answer of question (19) is:

D. Constructor of a class cannot be private.

Both data and functions can be either private or public.

Why not protected please explain any one?