@buntineMar 22.2005 — #Just a note, each answer you receive will differ slightly.
An abstract class should be created to represent an abstract concept, such as Shapes or Instruments.
For example, with instruments, you could set up an abstract class named Instrument. You would then sub-class it with a bunch of specific objects and conform to the layout of the super class (Instrument).
In the abstract class, you can make one or more methods abstract, which means they must be implemented in each subclass. <i> </i>public abstract class Instrument { public abstract void play(); }
public class Guitar extends Instrument { public void play() { } }
An abstract class cannot be explicitely instantiated (via the [b]new[/b] keyword). Rather, it should be sub-classed.