What is the purpose of the get/set methods?
What is a constructor? When is it called?
What is the difference between a public variable and a private variable?
What is the this variable, and what is it used for?
What is composition?
What is garbage collection, and when is it run?
What is an inner class, and what types of inner classes can you create?
What does "pass by reference" mean?
What is significant about the fact that object variables are really references to objects?