Array Pattern matching in Scala

ArrayPatternMatch.scala

val oneToFour = List(1, 2, 3, 4)

def sumElements(listOfInts: List[Int]) : Int = listOfInts match {
    case List() => 0 		// If it is an empty list, just return zero
    case head :: rest => head + sumElements(rest) // Otherwise, recurse and sum elements
}

sumElements(oneToFour)

This is a List, man, not an Array.

How can I match against an empty array?

Would the call of List() allocate a new object?

It seems an equivalence of List() is Array()?

  def countHoles(chars: Array[Char]): Int = chars match {
    case Array() => 0
    case _ => countHoles(chars.tail) + (chars.head match {
      case 'Q' | 'R' | 'O' | 'P' | 'A' | 'D' => 1
      case 'B' => 2
      case _ => 0
    })
  }