The following is an implementation of quicksort in Scala.

package de.vogella.scala.quicksort

/* Quicksort in Scala */
class Quicksort {
	def sort(a:Array[Int]): Array[Int] =
		if (a.length < 2) a
		else {
			val pivot = a(a.length / 2)
			sort (a filter (pivot>)) ++ (a filter (pivot == )) ++
				sort (a filter(pivot <))
		}
}

And a little test

package de.vogella.scala.quicksort

object Test {
  def main(args: Array[String]) = {
    val quicksort = new Quicksort
	val a = Array(5, 3, 2, 2, 1, 1, 9, 39 ,219)
	quicksort.sort(a).foreach(n=> (print(n), print (" " )))

  }
}

To learn more about Scala check out this introduction tutorial: Scala development with Eclipse

Update: this example is similar to the quicksort example from the excellent online Scala by Example book. Caution: The link is a pdf document.