Question

I understand why static functions can’t access non-static fields.
But if I send them an object of the class, will they be able to access his private fields? (not static)

Thanks a lot.

Answer 1

Yes they will. Here is a short sample:

#include <iostream>

using namespace std;

class A{
    public:
    A(): a(0) {}
    static void test(A& x) {
        x.a += 1;
    }
    private:
    int a;
};
int main() {
        A u;
    A::test(u);
        return 0;
}

Compiled on ideone. You should really learn to try such things on your own.