Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

why doesn't null.asInstanceOf[Int] throw a NullPointerException?

Since Int "does not conform to" AnyRef, I am not sure why it doesn't throw a NullPointerException according to Scala Reference on Section 6.3 :

asInstanceOf[T ] returns the “null” object itself if T conforms to scala.AnyRef, and throws a NullPointerException otherwise

And neither does null.asInstanceOf[Double], null.asInstanceOf[Boolean], null.asInstanceOf[Char] .

PS: My scala library is of version 2.9.0.1 and OS windows XP

like image 444
爱国者 Avatar asked Nov 27 '11 13:11

爱国者


1 Answers

In Scala Null is a type, which has a single value null. Since null is a value and every value in Scala is an object, you can call methods on it.

like image 96
agilesteel Avatar answered Oct 12 '22 19:10

agilesteel