'sizeof' a class

Continuation from last week. What is the sizeof of a class? Wrote a simple program as follows:

//Program tested on Microsoft Visual Studio 2008 - Zahid Ghadialy
#include<iostream>

using namespace std;

class A
{
  int a;
};

class B
{
  int b;
  int someFunc(void) {return b;}
};

class C
{
  void someFunc1(void) {};
  void someFunc2(void) {};
};

class D : public A
{
  void someFunc(void) {};
};


int main()
{
  cout<<"Size of class A = "<<sizeof(A)<<endl;
  cout<<"Size of class B = "<<sizeof(B)<<endl;
  cout<<"Size of class C = "<<sizeof(C)<<endl;
  cout<<"Size of class D = "<<sizeof(D)<<endl;
}

The output is as follows:

After finishing this, I found this interesting article here.