What OOP Isn't

http://hacksoflife.blogspot.com/2010/12/what-oop-isnt.html

by fogus • 16 years ago

20 18 16 years ago

hacksoflife.blogspot.com

wccrawford• 16 years ago

I like how he doesn't even try to defend his stance that inheritance is completely worthless. I would have said it's a LOT more useful.

jerf2• 16 years ago

It's a pretty popular idea in OO circles, in that if you are really interested in the topic you should already have heard the arguments. And blog posts have to stop somewhere.

You can start at http://c2.com/cgi/wiki?ArgumentsAgainstOop , and follow the links out of "Inheritance" for at least a decent start at the topic if you've never heard of this criticism.

davidmathers• 16 years ago

That page has top/topmind/tablizer written all over it.

http://c2.com/cgi/wiki?TopMind

http://www.geocities.com/tablizer/

raganwald3• 16 years ago

Implementation Inheritance is a massive can of worms, and a surprisingly emotional topic, but I feel fearless today. How do you feel it is useful?

diN0bot2• 16 years ago

off the top of my head: dynamic dispatch is a great way to re-use code, assuming the subclasses really have a "is-a" relationship.

this makes for a double whammy in terms of extensibility, since not only is the code literally more conducive to later changes, but it meets developer's expectations, too.

encapsulation and inheritance go hand-in-hand in my book, though i suppose encapsulation, and the necessary concept of interface contracts, is an axiom of sorts from which many other good practices can result, especially if there is also a culture of "communicating for extensibility by new developers later."

samg_• 16 years ago

I find that it can be valuable in a GUI toolkit. If I want to change a small part of a UI component, I can subclass it, change what I want, keep the rest, and classes that used the old component can use the new one too, because of subtype polymorphism.

Composition can work for a lot of these problems too. It depends on the scale of the modification, I guess.

akeefer• 16 years ago

There are lots of relatively coherent arguments already floating around the interweb around why composition is generally preferable to inheritance when it comes to code reuse; lots of people have strong feelings both ways.

I should point out, however, that many OO languages (like Java and C++) make inheritance much easier than composition, and as such inheritance seems more useful than it actually is, simply because it's all you've got. In languages that have better syntactic support for delegation and other compositional techniques, the usefulness of inheritance is significantly lessened. In other words, the usefulness of inheritance is more accidental (i.e. because you often don't have other good options) rather than inherent (i.e. because there simply aren't better options that are possible or available in other languages).

gnubardt• 16 years ago

he did link to another post he'd written elaborating on the subject

http://hacksoflife.blogspot.com/2007/01/inheritance-of-imple...

What OOP Isn't

Related Stories