"has a " relationship

hi all,
I want to know how to determine whether a given relationship falls under "is a " or "has a " relationship.
I know when we use extends to extend from a class then it falls under "is a " relationship. i am confused with interface relations especially.
Sorry if it is too basic/beginner question. Can someone explain pls?
Thanks in advance.
Sunitha. S

There are 3 of them:
is-a : When you extend. Ex: if class A extends B, then A is-a B.
has-a: When you contain something. Ex: If class A has a 'field' of class B, then A has-a B.
is-like-a : When you implement. Ex: if class A implements I, then A is-like-a I.
HTH,
Paul.

------------------
Get Certified, Guaranteed!
(Now Revised for the new Pattern)
www.enthuware.com/jqplus

Paul has already answered your question. Just like to add that
is-a relationship is Inheritance.
has-a relationship is Aggregation.
Zulfiqar.

[This message has been edited by zulfiqar raza (edited October 19, 2000).]

Thanks bunches Paul and Zulfiqar. Appreciate your prompt reply.
Sunitha. S