Quick OOP question...

Question

If I make a class, and then make the the class an object in another class. Then do stuff, and access vars and such. If I need to use some vars from the class I made the object from(use them from a different class), do I make a new object for that class?
It's confusing so here's an example:
class Yo{
int sup = 5;
class ObjectThing{
Yo y = new Yo();
y.sup++;
class ObjectThingy{
Yo y = new Yo();
//Now, do I make another object of the same thing, is that the 'right' way to do it, or is there a better way? Its just now I have 2 Yo y = new Yo() objects.
y.sup++;
}

Answer 1

Not if you want to adhere to the OO principle of data hiding:
class Yo
  private int a;
  public int a()
    return a;
  public void a( int in )
    a = in;
class Foo
  Yo y = new Yo();
  // do this in a constructor
  public Foo()
    y.a( y.a() + 1 );  // does the same thing as add 1 to y's a
}see how Foo cannot directly access Yo's a variable? That is data hiding
if you want to allow the outside world to access it Yo can have get
and set methods like the ones shown.