class dog
{
 public:
  void print_data();
};


class collie : public dog
{
 public:
  static const int array[];
};


class spaniel : public dog
{
 public:
  static const int array[];
};


const int spaniel::array[2]={111,222};
const int collie::array[2]={333,444};

void dog::print_data()
{
  cout << array[0] << "\n";
  cout << array[1] << "\n";
}

class Dog {
protected:
    int array[2];
public:
     inline void print_array() {
          cout << array[0] << endl << array[1] << endl;
     }
};

class Collie : public Dog {
public:
 Collie() { // override constructor
   array[0] = 5;
   array[1] = 6;
  }
};

class Spaniel : public Dog {
public:
  Spaniel() {
     array[0] = 7;
     array[1] = 8;
  }
};

int main() {
  Collie c;
  Spaniel s;
  c.print_array();
  s.print_array();
  return 0;
}

class dog&#10{&#10private:  // it does no harm to explicitly declare access privilege...&#10&#10	/*&#10	I don't know how well you know C++ but there are a few things to note.&#10&#10	First, the const keyword modifies the thing to its _left_&#10	It's only a hack that, if there's nothing to its left, it modifies what's to its right.&#10&#10	Second, private member functions can be _defined_ by child classes, they&#10	just can't be _called_ by child classes.  See the distinction?&#10&#10	Thirdly, the "= 0" modifyier, if you've never seen it before, means&#10	that the function has no definition.  That means you can't actually make&#10	an instance of dog.  You must make instances which define the "= 0" member&#10	function--typically the children...&#10&#10	I hope this all makes sense to you!    */&#10	int const * get_array_data() = 0;&#10&#10public:&#10	void print_data();&#10};&#10&#10&#10class collie : public dog&#10{&#10private:&#10	static int const array[];  // there's no reason to make this public!&#10&#10	int const * get_array_data()&#10	{&#10		return array;&#10	}&#10};&#10&#10// keep your variables near the clases you define them in!&#10int const collie::array[2]={333,444};&#10&#10&#10class spaniel : public dog&#10{&#10private:&#10	static int const array[];  // there's no reason to make this public!&#10&#10	int const * get_array_data()&#10	{&#10		return array;&#10	}&#10};&#10&#10int const spaniel::array[2]={111,222};&#10&#10&#10void dog::print_data()&#10{&#10	int const * array = get_array_data();&#10	cout << array[0] << "\n";&#10	cout << array[1] << "\n";&#10}&#10&#10

class dog
{
 public:
  int const *numb;
  void print_data()
  { cout << *numb << "\n"; };
};


class collie : public dog
{
 public:
  static int const numb;
  collie(){dog::numb=&collie::int_numb;};
};
int const collie::int_numb=111;

class spaniel : public dog
{
 public:
  static int const int_numb;
  spaniel(){dog::numb=&spaniel::int_numb;};
};
int const spaniel::int_numb=555;

/* not valid C++ but I'd like it to be :) */
class dog
{
 public:
  virtual int numb;
  void print_data()
  { cout << numb << "\n"; };
};

class spaniel
{
public:
  static int const numb;
};

/* etc.... */

void do_something_that_includes_printing(dog* dog_obj) {
	// do stuff...

	// how can the compiler know which dog this is?
	dog_obj->print_data();
}


int main() {
	dog* dog_obj = new collie();
	do_something_that_includes_printing(obj);
	delete dog_obj;

	dog_obj = new spaniel();  // reusing the pointer
	do_something_that_includes_printing(obj);
	delete dog_obj;

	return 0;
}