Question

The designer of a class C mentions to you that he needs to add a default constructor to C. Which of the following is almost certainly true? C has const data members The designer should write his own destructor for C C has const member functions It is not currently possible to declare an array of C The designer should write his own assignment operator for C. It is not currently possible to declare any variables of type C.

Which of the following is almost certainly true? (Can be as many selections as possible)

		C has const data members
		The designer should write his own destructor for C
		C has const member functions
		It is not currently possible to declare an array of C
		The designer should write his own assignment operator for C.
		It is not currently possible to declare any variables of type C

Answer 1

Ques: Which of the following is almost certainly true? (Can be as many selections as possible)

Answer:

• C has const data members

Reason: When a class has const data members, that const data member can only be initialized using a constructor (default constructor in this case) and there is no other way of doing that.
All other options do not depend upon the default constructor. So, the only option true is the first one.

Code to demonstrate how to initialize a const data member using a default constructor:-

class C{
private:
    const int a;
    
public:
    //Default constructor to initialize const data member a to 0
    C() : a(0) {}
};

If you remove the default constructor then you'll not be able to declare any object of class C.