Where would you use a friend function vs. a static member function?

Question

We make a non-member function a friend of a class when we want it to access that class\'s private members. This gives it the same access rights as a static member function w

Answer 1

Static function can only access members of one class. Friend function has access to several classes, as explained by the following code:

class B;
class A { int a; friend void f(A &a, B &b); };
class B { int b; friend void f(A &a, B &b); };
void f(A &a, B &b) { std::cout << a.a << b.b; }

f() can access data of both A and B class.