In context of C++, which of the following is valid statement ?

Question

Accepted Answer

The correct option is (4):
The statement that "Keywords private, protected and public may appear in any order and any number of times in a class" is absolutely valid in C++ programming. These access specifiers serve as labels to divide the class definition into sections, controlling the visibility of the members declared *after* them until the next specifier or the end of the class is reached. A programmer might need to interleave different access levels for specific design reasons, such as grouping related members or separating public methods that use a private helper method, and C++ syntax explicitly supports this flexibility without imposing any restrictions on the order or frequency of the specifiers.

The incorrect option is (1):
The statement that a "Friend function of class is always a member function of that class" is incorrect. By definition, a **friend function** is a non-member function or a member function of another class, that is granted special access to the private and protected members of the befriending class. Its primary utility comes from the fact that it is *not* a member of the class, allowing it to perform operations that involve two separate classes or to act as a global utility function, while still maintaining privileged access to the class's internal data. If a function is a member of the class, it does not need the `friend` keyword to access its own private or protected data.

The incorrect option is (2):
The statement that the "Value of static data member cannot be manipulated once assigned" is false. A static data member is primarily a class-wide variable that has only one copy shared by all objects of the class, and it exists even when no objects are instantiated. Unlike a `const` member, a regular **static data member** is a mutable variable whose value can be freely modified (manipulated) by any authorized member function or external function throughout the program's execution, exactly like a global variable with class scope. The immutability suggested by this option is not an inherent property of static members.

The incorrect option is (3):
The statement that "Static data member of a class can be accessed only by static member function of that class" is incorrect. **Static data members** are accessible by *all* member functions of the class, regardless of whether they are static or non-static. A non-static member function, when called through an object, has full access to both static and non-static members. Additionally, if the static data member is declared in the `public` section, it can be accessed by *any* code outside the class using the class name and the scope resolution operator (`::`), which is a clear violation of the "only by static member function" restriction.