Categories of Variables

• Categories of variables
  1. Instance fields (balance in BankAccount)
  2. Local variables (newBalance in deposit method)
  3. Parameter variables (amount in deposit method)
• An instance field belongs to an object
• The fields stay alive until no method uses the object any longer
• In Java, the garbage collector periodically reclaims objects when they are no longer used
• Local and parameter variables belong to a method
• Instance fields are initialized to a default value, but you must initialize local variables