[roenxi]

I'm no expert at OOP, but never have I seen a student who telegraphs a look of comprehension after seeing an example of classes involving animals. I've seen many who get more confused.

Classes are a neat way of hiding implementation detail behind a mini-api that has reasonable code-hygiene benefits and works well in a team setting. None of these things have anything in common with meowing cats.

There was a classic on HN a while ago [1] illustrating how blindly guessing an OOP hierarchy for a problem isn't going to help. Throw that at a learner without thinking too hard, and they are going to question what the benefits of OOP even are - it doesn't always simplify a problem.

[1] https://www.quora.com/Is-abstraction-overrated-in-programmin...

[repsilat]

Mm. For me there are only a few reasons to use inheritance:

- Common operations between classes, operating on common data, but requiring an external API (so composition is a pain because you would have to proxy those actions to the member.)

- Restricting/specifying the types of objects you can store in a container if you are programming in a language/codebase that cares about that (incl. the C++ "definitely has the vtable I want".)

And maybe that's it? I guess all the taxonomy talk might be useful in the first hour of learning about inheritance, but after that I think the analogy should give way to more concrete "what are the code and data doing?" angle.

[humbleMouse]

I agree. Inheritence is useful in a very small amount of situations and can be the start of a long abstract chain of bullshit if other devs are allowed to build more funtionality on top...

[ninkendo]

I’ve only ever seen inheritance make sense in UI toolkits. That’s literally it.

It’s like if someone took the cascading idea of CSS and decided “this works so well for UI styling, let’s build a language paradigm out of it and convince people they need to express every problem in terms of it.”

[fenomas]

> never have I seen a student who telegraphs a look of comprehension after seeing an example of classes involving animals

I think it's a classic case of teaching people the answer before the question.

Animal examples explain what types and subtypes are, but the thing that warrants explaining is why and when it's useful to separate things into types and subtypes, and animal examples are terrible for that. If someone asks "should Cat and Dog inherit from Quadruped? Mammal? Pet?" there's no useful answer.

[andreareina]

HN thread: https://news.ycombinator.com/item?id=16047497