What’re the main differences between Kotlin and Scala? I mean, I started using Kotlin this weekend a...

# getting-started

[Filipe Duarte]

What’re the main differences between Kotlin and Scala? I mean, I started using Kotlin this weekend and feel many similarities for an intermediate programmer between both languages.

[nanodeath]

as someone who's learning Scala, on the surface there are a lot of similarities in syntax

[nanodeath]

but Kotlin aims to be more pragmatic and easier to learn and use. also aims for good Java interop

[nanodeath]

and there were a lot of...interesting...decisions made in the Scala language, like creating their own collections framework, or implicit type conversions, or IIRC the way generics are implemented

[Filipe Duarte]

What features Kotlin has, and Scala doesn’t?

[Filipe Duarte]

Well, I will use both hahaha

[Roukanken]

the way generics are implemented

what did Scala do with generics?

[ephemient]

I'm not sure what Max is referring to there; they use similar declaration-side variance as Kotlin. syntax is oddly `[+T]`/`[-T]`/`[T]` instead of `<out T>`/`<in T>`/`<T>` though

[ephemient]

IMO the main difference is that Kotlin avoids many of the more questionable design choices of Scala

[ephemient]

what does Scala's _ mean? long list of rules. what does Kotlin's it mean? simple.

[ephemient]

and yeah, Kotlin is pragmatic. Scala has some features like non-local returns and structural typing that are simply expensive to implement on the JVM, and Kotlin just doesn't have them.

[nanodeath]

I just remember reading the Scala book and there being a lot of sections about the type system (half the book? more?) and never actually understanding generics

[ephemient]

well, Scala does have a lot of type-related machinery, with more manipulation being possible at compile-time (such as mixin traits) and runtime (such as reified generics backed by implicit values), but I wouldn't call those part of generics exactly

[nanodeath]

I'm probably misremembering 😅 it was a few years ago.

but yeah, relearning Scala and things like ++: and +: for various collection manipulations, plus how you can say new Instance() with Interface1 with Interface2 is...on that list of interesting choices

[ephemient]

(to be fair, object : Instance(), Interface1, Interface2 {} is legal in Kotlin, but there are certain patterns that can't be expressed. aside from some inherent awkwardness, Scala has a self type and Kotlin doesn't, which makes a difference for some of those uses)

[Filipe Duarte]

I didn’t use Generics yet, but I studied and felt a bit complex. I think it is essential to know to program more deeply.
I’m not a developer but a Ph.D. student and a data scientist. I use Python and have been studying Scala and Spark.

[Filipe Duarte]

So, significant differences are related to advanced things