[dyarosla]

None of those things are necessarily fundamental notions in OOP so much as they are core constructs in many OOP languages. It's quite trivial to find multiple examples for why inheritance causes far more problems in many cases than when using composition- rigid class hierarchies and fragile superclasses are some such examples (problems: extendability/maintainability and high coupling). Patterns are ways to semi-cleanly work within an OOP design, but you'll find that it's often the case that a lot of verbosity needs to come along for the ride- working towards solving how to structure class hierarchies more than solving the actual problems those classes are meant to solve.

There's a reason why composition is preferred over inheritance. There's also good reason why some programmers will take it to the extreme and say that it ALWAYS causes more problems. Some languages lack of providing an appropriate aggregation alternative generally keeps inheritance alive.

Some people will hold onto their positive notions about inheritance too, and that's fine, but there's a reason why many people advocate strongly against it (and why some modern language designers skip it altogether!)

[euyyn]

> Some languages lack of providing an appropriate aggregation alternative generally keeps inheritance alive.

I might not be understanding well, but are you talking of languages that happen to have no _composition_? But do have inheritance? Sounds like those with inheritance are a strict subset of those with composition (which in turn would be all but fringe languages).

[dyarosla]

No I'm talking about a lack of language constructs that make composition a pain and inheritance a quick fix: forwarding. Inheritance is often used improperly because writing forwarding methods to delegates is a pain. IS-A/HAS-A goes OUT-A the window: in many cases ushers developers to adopt it because it requires less typing.

[soulbadguy]

It seems to me that you are just explaining what the parent was saying. My point is not inheritance is good/bad or usefull, my point was that OOP doesn't imply inheritance it's just one of the many ways OOP languages reuse code.