4 ms·

You haven't had to declare the type since Java 10. var myThing = new MyThing();

• riku_iki 3y ago
  still need it for class members, unlike in some other languages.
  • kaba0 3y ago
    Most languages don’t do type inference in “signatures” (function, but also class/struct members), as it would give you negligible benefit, a huge cost for the compiler and is commonly thought of as a bad practice. Out of Scala, Rust, I believe even Kotlin, none do inference in these places. Even Haskell, which does infer function signatures as well, need explicit type annotation for `data` definitions.
    • riku_iki 3y ago
      typescript does such inference. I disagree with you about huge cost for the compiler and benefits are the same as in normal code block: reducing boilerplate.
      • kaba0 3y ago
        Typescript’s type system is deliberately not sound though. In general, there is no type inference available for OOP type-hierarchies as opposed to a more Haskell-like type system, where Hindley-Milner works
        • riku_iki 3y ago
          I don't have strong knowledge in types theory, but why class C { a: int = 0; } can't be replaced with class C { a = 0; } ? what issues it brings?..
          • kaba0 3y ago
            That can. But what about a field that is not initialized there?
            • riku_iki 3y ago
              obviously you would need to provide type.
• matsemann 3y ago
  Yup, hence "used to", but I could be clearer it's no longer an issue.
  • vips7L 3y ago
    My issue with your statement is that you're pretending that this was a recent issue. This hasn't been an issue in over half a decade. Do we point out bugs in libraries from 6 years ago? Are we critical about what other languages looked like then? In my experience, Java is the only one that gets this criticism.