inheritance and aggregation

[java_fun2007]

hi,
I have a question about this relation

http://img143.imageshack.us/img143/1...problemeq3.png

Class A has aggregation relationship with Class B

Class B has aggregation relationship with Class C

Class B has Inheritance relationship with Class D

Class D has aggregation with Class E

Class C and Class E have almost the same attributes and methods, is that mean that Class E has extended the Inheritance too or should I write the attributes and methods again?? :confused:

thanks

[java_fun2007]

Do I need an abstract class? :rolleyes:

[dmacvittie]

Not an easy question to answer with the information you have provided. If all of C is in E or all of E is in C, then yes, making one a subclass of the other makes sense in most cases.

Aggregations don't generally need any form of relationship - the relationship is defined by the fact that one holds a collection of the other.

Hope that helps!

Don.

[java_fun2007]

yeah I guess I should add inheritance between those two classes too :)

Thanks for you help!

Dan