Scala underspecified types

Question

I have the following spark code snippet .

But get the following error:

:8: error: missing parameter type.

which happens here:

       val index:Int= col1(i) ; tokened +=splitted(index) + " " ;  } } 
                     ^

I can't work out where it steps from as it seems like i've specified all properties. I also need to return the string so for the method to be string => string (currently it's string -> unit) This is my first time ever coding in scala so apologies if this is a stupid question

line => { var col1:Array[Int] = Array(1,2) ; var tokened:String = "" ; 
    var splitted:Array[String]=line.split(" ") ;  
    for (i<- 0 to col1.length) { 
        val index:Int= col1(i); 
        tokened +=splitted(index) + " " ;  
    } 
} 

Answer 1

I guess this is what you need:

(line: String) => { /* Previously missing type annotation */
  var col1:Array[Int] = Array(1,2)
  var tokened:String = ""
  var splitted:Array[String]=line.split(" ")

  for (i<- 0 to col1.length) { 
    val index:Int= col1(i)
    tokened += splitted(index) + " "
  }

  tokened /* Return value */
}

In order to make the function type explicit, you could store the anonymous function in a function-typed variable:

val f: (String => String) = line => { ... }