What is the purpose of friend function and friend classes?

What is the purpose of friend function and friend classes?

What is Friend Function? Friend functions of the class are granted permission to access private and protected members of the class in C++. They are defined globally outside the class scope.

Can we use friend function in inheritance?

No, friend functions are not inherited. Why would a base class function work on a derived class object? Because friend function is using the data members available in base class only.

What is the main reason for creating a friend class?

A friend class is a class that can access the private and protected members of a class in which it is declared as friend. This is needed when we want to allow a particular class to access the private and protected members of a class.

What are the advantages of using friend classes?

Benefits of friend function A friend function is used to access the non-public members of a class. It allows to generate more efficient code. It provides additional functionality which is not normally used by the class. It allows to share private class information by a non member function.

What is friend function when it is compulsory?

Declaring a function as a friend of a class is required only if that function is not a member of the class and it needs access to one or more of the class’s private members.

How friend function violates the philosophy of OOP?

A friend function in the class declaration doesn’t violate encapsulation any more than a public member function violates encapsulation: both have exactly the same authority with respect to accessing the class’s non-public parts.)

What is difference between friend class and inheritance?

In C++, friendship is not inherited. If a base class has a friend function, then the function doesn’t become a friend of the derived class(es). For example, following program prints error because show() which is a friend of base class A tries to access private data of derived class B.

What is the difference between friend class and derived class?

Its only difference occurs in fact with inheritance: When a class inherits another one, the members of the derived class can access the protected members inherited from the base class, but not its private members. With protected , all public members of the base class are inherited as protected in the derived class.

What is the difference between friend function and friend class give an example?

Friend function is a function that is able to access the private and protected members of a class. In contrast, a friend class is a class which help in accessing the private members of a class. A friend function is declared by including its prototype inside the class, antecede it with the keyword friend.

What is the difference between friend function and member function?

Friend function is a non-member function that has access to private and protected members of a class. It is not in the scope of the class in which it is declared. Member function is in scope of the class in which it is declared. A friend function cannot be called using object of the class.

What is the purpose of a friend function?

In object-oriented programming, a friend function, that is a “friend” of a given class, is a function that is given the same access as methods to private and protected data. A friend function is declared by the class that is granting access, so friend functions are part of the class interface, like methods.

What is friend function explain its advantages with the help of an example?

One advantage of the friend function or class is that we can access the private and protected data of the class. For Example, if we are implementing a linked list, then we can make the linked list class as a friend of the node class and access its data as the linked list consists of nodes.