object Demo
{
  def disp(x : Option[Int])
  {
    println(x.isEmpty)
    println(x.getOrElse(0))
  }

  def main(args : Array[String])
  {
    var b  = Map("Hannah" -> 12, "Hadley" -> 1);

    disp(b.get("Hannah")); // false, 12
    disp(b.get("Lin")); // true, 0
  }
}