how to declare an annonymous function in scala with multiple returns?

Question

I want to declare a constant value MyValue of type string using the result of an anonymous function. Right now I have something similar using a declared function getValue

// Start writing your ScalaFiddle code here
val n = 23

def getValue(): String = {
  if (n == 1) return "One"
  if (n == 2) return "Two"
  return "Another value"
}

val MyValue = (getValue())

println(n)
println(MyValue)

How could I use an anonymous function instead? So it would look like this

val n = 23

val MyValue = (() => {
  if (n == 1) return "One"
  if (n == 2) return "Two"
  return "Another value"
})()

println(n)
println(MyValue)

But this gives me the following error:

ScalaFiddle.scala:7: error: return outside method definition
    if (n == 1) return "One"
                ^
ScalaFiddle.scala:8: error: return outside method definition
    if (n == 2) return "Two"
                ^
ScalaFiddle.scala:9: error: return outside method definition
    return "Another value"
    ^

Don't use `return` in Scala. More details in [this blog post](https://tpolecat.github.io/2014/05/09/return.html). [This answer](https://stackoverflow.com/questions/17754976/scala-return-statements-in-anonymous-functions) might also help. — Oleg Pyzhcov, Apr 15 '21 at 18:12
Why a lambda of no arguments that you want to call immediately? Why not just assign the whole `if` expression to your value? — Luis Miguel Mejía Suárez, Apr 15 '21 at 18:18

score 2 · Accepted Answer · answered Apr 15 '21 at 18:12

2

You can remove return and use else in the conditionals:

val MyValue = (
    () => {
        if (n==1) "One" 
        else if (n==2) "Two" 
        else "Another value"
    }
)()

answered Apr 15 '21 at 18:12

mck

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This way it always returns `Another value` – akko Apr 15 '21 at 19:20

how to declare an annonymous function in scala with multiple returns?

1 Answers1