3 ms·

List(1,2,3,4) filter isEven sum println error: type mismatch; found : Unit required: Numeric[?] List(1,2,3,4) filter isEven sum println

• virtualwhys 13y ago
  I didn't write what you wrote ;-) foreach takes a collection and applies some function (in this case println). I've actually had a use case for what you're trying do, so created an extension method on Any, which means you can then do, on Any-thing: (list filter isEven sum).echo I also hate typing "println". "echo" I can bang out instantly, and can do so on any expression, before or after its definition.
• ponzao 13y ago
  `sum` does not accept a function as a parameter, the original example had an `foreach` instead of `sum`. list filter isEven foreach println As a side note omitting that many commas and parenthesis is very rare at least based on the Scala projects I've worked on. The above example is equal to the one below: list.filter(isEven).foreach(println)
  • virtualwhys 13y ago
    Good points, I tend to mix it up, rarely going parens-free style, but also not parens by default either. If you wanted to be really explicit you could do: list.filter(x=> isEven(x)).foreach(x=> println(x)) yuck ;-)
    • ponzao 13y ago
      That example is not quite equivalent, because now you are not passing `isEven` or `println` as arguments, you are passing anonymous functions that call `isEven` and `println`.