Solution

The correct answer is A, D, E Only.

Key Points

​Here is the detailed evaluation of each statement to find the correct answer:

A. The ++ operator can be overloaded to perform decrementation of a variable.

True. While it is terrible programming practice because it violates the expected semantics of the operator, C++ allows you to write whatever logic you want inside an overloaded operator function. You could technically make operator++ subtract values.

B. It is necessary that a constructor in a class should always be public.

False. Constructors can be private or protected. Private constructors are frequently used in specific design patterns, such as the Singleton pattern, to prevent other classes from instantiating the object directly.

C. Size of an object is equal to sum of sizes of data members and member functions within the class.

False. The memory allocated for an object only includes its data members (and potentially padding for alignment or a virtual pointer if virtual functions exist). Member functions are stored separately in the code segment and do not increase the physical sizeof() the object.

D. A static data member is useful when all objects of a class are to share a common item of information.

True. A static data member belongs to the class itself rather than any specific object. Only one copy of the static variable exists in memory, and it is shared by all instances of that class.

E. The this pointer always contains the address of the object using which the member function is being called.

True. In C++, the this pointer is a hidden, implicit parameter passed to all non-static member functions. It points directly to the specific object instance that invoked the function.

Conclusion:
Statements A, D, and E are true.

Correct Answer: Option 3 (A, D, E Only)