What does the arrow (“->”) operator do in Kotlin?

Question

Probably a little bit broad question, but the official documentation doesn\'t even mentioning the arrow operator (or language construct, I don\'t know which phrase is more a

Answer 1

The -> is a separator. It is special symbol used to separate code with different purposes. It can be used to:

• Separate the parameters and body of a lambda expression

  val sum = { x: Int, y: Int -> x + y }
  

• Separate the parameters and return type declaration in a function type

  (R, T) -> R
  

• Separate the condition and body of a when expression branch

  when (x) {
      0, 1 -> print("x == 0 or x == 1")
      else -> print("otherwise")
  }  
  

Here it is in the documentation.