int addFiveAction(
  params: Map<String, String>) {
    String nbS = params.get("number");

    if(nbS != null) {
        if(!nbS.isEmpty()) {
            try {
                int nb = Integer.parseInt(nbS)
                return nb;
            } catch(NumberFormatException e) {
                return 0;
            }
        }
    } else {
        return 0;
    }
}

int addFiveAction(
  params: Map<String, String>) {
    String nbS1 = params.get("n1");
    String nbS2 = params.get("n2");

    if(nbS1 != null) {
        if(!nbS1.isEmpty()) {
            try {
                int nb1 = Integer.parseInt(nbS1)
                if(nbS2 != null) {
                    if(!nbS2.isEmpty()) {
                        try {
                            int nb2 = Integer.parseInt(nbS2);
                            return nb1 + nb2;
                        } catch(NumberFormatException e) {
                            return 0;
                        }
                    }
                }
            } catch(NumberFormatException e) {
                return 0;
            }
        }
    } else {
        return 0;
    }
}

def addNumbersAction(
  params: Map[String, String]
): Int = {
    val i1 = getInt("n1", params)
    val i2 = getInt("n2", params)
    i1.getOrElse(0) + i2.getOrElse(0)
}

val myVar =
    "obviously a string"

val myVar = List( "obviously"
        , "a"
        , "list"
        , "of"
        , "strings"
        )

def reverse(
  xs: List[A]
): List[A]

reverseProp ::
    Eq a =>
    [a] -> [a] -> Bool
reverseProp xs ys =
    reverse (xs ++ ys) ==
        reverse ys ++ reverse xs

λ> quickCheck reverseProp
+++OK, passed 100 tests.