Please explain use of Option's orNull method

Question

Scala\'s Option class has an orNull method, whose signature is shown below.

orNull [A1 >: A](implicit ev : <:<[Null, A1]) : A1

Answer 1

orNull purpose is first of all in ensuring compatibility of Option with Java. Though usage of null is discouraged in Scala, some interfaces may expect to get nullable references.

orNull has a straightforward implementation:

def orNull[A1 >: A](implicit ev: Null <:< A1): A1 = this getOrElse null

According to this, null will be returned not only for boxed nulls (Some(null)), but also for None (e.g., if you call None.get, exception will be thrown).

Implicit parameter checks, if the boxed value is nullable.

Good usage example can be found right in the comments to orNull:

val initialText: Option[String] = getInitialText
val textField = new JComponent(initialText.orNull,20)