Option
  • Scala Option[ T ] is a container for zero or one element of a given type
    1. object Demo
    2. {
    3. def disp(x : Option[Int])
    4. {
    5. println(x.isEmpty)
    6. println(x.getOrElse(0))
    7. }
    8.  
    9. def main(args : Array[String])
    10. {
    11. var b = Map("Hannah" -> 12, "Hadley" -> 1);
    12.  
    13. disp(b.get("Hannah")); // false, 12
    14. disp(b.get("Lin")); // true, 0
    15. }
    16. }