Question

I know the rule of using inheritance when there is an is-a relationship, and composition when there’s a has-a relationship, but are the two mutually exclusive/replacements for one another or would there be a case where you should use both in the same class?

I’ve Googled a lot but only found articles explaining when you use each, rather than both.

Thanks

Answer 1

They are not mutually exclusive. Example: Boat and Sailboat. Sailboat is-a Boat, but it has-a Sail, which other Boats may or may not have.