Important Class Terms

• Class: A template that creates objects.  Think of it as a rubber stamp.
• Objects are the images that the stamp makes.  They are instantiated from the class, because they are an instance of that class when constructed.
• All of the programming you do will be inside classes.  Java provides some default classes for you as part of the standard Java library.
• instance fields or attributes are the data inside an object.
• methods operate on data in an object.  They are the window through which other objects can access the instance fields.  In a well designed object oriented program, the instance fields should not be directly available to other objects.
• Often called black box behavior.
• extending a class is just that-you can specify a superclass of a class that you write.  The class that you write, called the subclass, inherits all of the attributes and methods of the superclass, until or unless those are overridden.


 Object Terms
 

Created by:  Brandan Jones January 4, 2002