Scala Map foreach

Question

given:

val m = Map[String, Int](\"a\" -> 1, \"b\" -> 2, \"c\" -> 3)
m.foreach((key: String, value: Int) => println(\">>> key=\" + key + \",          


        

Answer 1

Excellent question! Even when explicitly typing the foreach method, it still gives that very unclear compile error. There are ways around it, but I can't understand why this example does not work.

scala> m.foreach[Unit] {(key: String, value: Int) => println(">>> key=" + key + ", value=" + value)}
:16: error: type mismatch;
 found   : (String, Int) => Unit
 required: (String, Int) => Unit
              m.foreach[Unit] {(key: String, value: Int) => println(">>> key=" + key + ", value=" + value)}
                                                         ^