[randomdata]

All OOP languages use message passing, but perhaps you mean languages with objects that are not oriented?

While not completely identical to Smalltalk's message passing design, the Qt project once went to all the trouble of building their own compiler just to be able to graft message passing onto C++. I think that goes to show that there really is a difference – otherwise, why not use the standard constructs C++ offered?

Whether or not that difference makes for better software is debatable. It does seem that at one time it did lend itself exceptionally well to GUI programming. NeXTSTEP/macOS/iOS also would never have been what they are without OOP. But we've also learned some programming tricks along the way, so it may not even shine there anymore. Swift, for example, has given up on OOP (except where @objc mode is enabled) and it seems like it manages to do quite well with GUIs (granted, having @objc mode to fall back on clouds that somewhat).

[alex_smart]

I mean that, to me, the difference between message passing and method calling is not significant enough to say that these languages are following different programming paradigms - like you say OOP vs languages with objects.

Afaict the difference between Smalltalk and Objective-C style message passing and Java and C# style method calling is purely syntactic.

[randomdata]

> Afaict the difference between Smalltalk and Objective-C style message passing and Java and C# style method calling is purely syntactic.

doesNotUnderstand:/forwardInvocation: isn't different? That is not just syntactical. How would you even begin to orient your objects without like functionality?

I agree that if you squint really hard they look the same. But if we say "they are all the same", what are you trying to communicate when you say OOP? Virtually all programming languages we use have objects. You may as well drop the OO and just use "programming". It would communicate the same intent.

[alex_smart]

>doesNotUnderstand:/forwardInvocation: isn't different? That is not just syntactical. How would you even begin to orient your objects without like functionality?

Not sure what you mean. Could you please elaborate?

> what are you trying to communicate when you say OOP?

The idea of using dynamic dispatch as a means of taming complexity.

[randomdata]

> Not sure what you mean. Could you please elaborate?

I'm not sure where your understanding falls short. Which part are you unsure of?

> The idea of using dynamic dispatch as a means of taming complexity.

Erlang utilizes the idea of dynamic dispatch as a means of taming complexity. What is it in particular about its dynamic dispatch mechanisms that you want me to know when you call attention to its OOP properties?

C++ also utilizes the idea of dynamic dispatch. When you call attention to its OOP properties, are the particulars being pointed to the same as in Erlang, or does it mean something different in the context of that language?