Welcome to JavaRanch
I think Rob will probably want to move this
thread to "beginners.2
I think you will have to look in Google . . .
But I found
Aggregation and
Object composition on Wikipedia. I think those two links eventually lead to the same page!
Both aggregation and composition can be described by a HAS-A relationship. Aggregation: a car HAS-A driver, but if you take the driver from the car the car is still a working car.
Composition: a car HAS-AN engine, but if you take the engine from the car the car is no longer a car in the fullest sense of the
word; neither the car nor the engine will "work."
You mean "inheritance" not "association." That is described with an IS-A relation, and should also fulfil Barbara Liskov's substitution principle, which I haven't got time to describe. I couldn't find "inheritance" in wikipedia.
You should find details in any object-oriented programming book, but composition is usually much easier to handle than inheritance.
"Association" is a compiler term; there is a bit about it in Wikipedia under the name
Operator associativity. [ June 02, 2008: Message edited by: Campbell Ritchie ]