class(with static member) initialization in c++

I was trying to understand friend functions and I found myself writing the following code

though I have understood the friend functions, this code leaves me with new questions:

1. how does the class initialise here when I havn't instantiaied any object

I know static member is shared by all objects of the class and is initialized to zero when the first object is created

2. at what point does the variables base_i and derived_i get assigned to respective values from code

I suppose it happens at return derived::derived_i + derived::base_i;

3. if so, does that also allocate the memory for all the other members of class at that point, specifically also for newVar in this case

#include <iostream> class base { private: static int base_i; float newVar; public: friend int addClasses(); }; int base::base_i = 5; class derived : private base { private: static int derived_i; public: friend int addClasses(); }; int derived::derived_i = 3; int addClasses() { return derived::derived_i + derived::base_i; } int main() { std::cout<<addClasses()<<std::endl; }