Hello Scala

Hello World!

def hello = println("Hello world!")

Functional style

def append[A](xs: List[A], ys: List[A]): List[A] =
  if (xs == Nil) ys else xs.head :: append(xs.tail, ys)

def map[A, B](f: A => B, xs: List[A]): List[B] =
  xs match {
    case Nil => Nil
    case h::t => f(h) :: map(f, t)
  }

def increment(x: Int): Int = x + 1

Usage

scala> val a = map(increment, List(1,2,3,4,5))
a: List[Int] = List(2, 3, 4, 5, 6)