Question

Can some one please explain the scope of int A and int B in the void func() and in void func1()?

class C {
  struct S {
    int A;
  };

  int B

public :
  void func(){
  }
  void func1(){
  }
};

Answer 1

Not sure I fully understand what you’re asking for, but if I do, I’ll try to answer.

Functions func() and func1() are member functions of C, so they have identical access to the exact same names here. Variable B, being a member variable of C, can be referred directly withing func() and func1() without qualifying it with any namespace.

Variable A on the other hand, being a public, non-static member variable of S, requires first instantiating an object of type S before being accessed, like this:

void func()
{
    S s;
    B = 0; // Directly accessible, member variable of `C`
    s.A = B; // A is a non-static member variable of `S`, requires an object
    A == 3; // ERROR! A is not a member variable of C
}