object Reverse { def reverse[T](l: List[T]): List[T] = FoldLeft.foldLeft(l, Nil: List[T])((b, a) => a :: b) def main(args: Array[String]): Unit = { println(reverse(Nil)) println(reverse(List(1))) println(reverse(List(1, 2, 3, 4))) } }
List() List(1) List(4, 3, 2, 1)