C++ Programming - OOPS Concepts - Discussion

We can define a friend function (i.e a normal function can be a friend of a class or a member function of a class can be a friend function of another class), friend class (i.e member function of a friend class can directly access private and public members of that class, if which it is defined as friend) and also friend operator function (i.e operator function of one class can be defined as friend function in another class). But object is a run time entity.

I don't know whether it is correct. The operator functions are used in the concept of operator overloading and type conversion. Operator can be overloaded as a member function or friend function. Therefore an operator function can be a friend function.

Object is a variable of class type hence there is no sense to declare it as a friend. If it is declared as friend then where we use it think about it. Even if we make use of function as friend then it can be used to access other class private data.

Friend function is a function which is not the member of the class but take part in class to pass arguments. Similarly a class can be a friend but an object cannot because it is an instance of the class.

Friend function is used to pass arguments in a class. Class can also be friend but an object is cannot be friend as it is an instance of a class.

Any type of function can be made friendly exception-static. But object are the instance of class that cannot be made friend.

Class and functions can only be friend. Objects are instance of class, they cannot be defined by user as friend.

Objects cannot be defined as friend by a user since it is just instance of a class.

Instance of class means object works during the execution of program.

How can operator function be friend function?even I didn't get it?