"On the Java platform, numbers are physically stor...

# announcements

[PandaH.]

"On the Java platform, numbers are physically stored as JVM primitive types, unless we need a nullable number reference (e.g. Int?) or generics are involved. In the latter cases numbers are boxed." What does it mean by boxed?

[Marcin Bak]

wrapped in Java instance of Integer class (for example)

[Michael de Kaste]

What Marcin said

A java int is a JVM primitive and always needs to have a value.
In order to make that int nullable; e.g. have no value. You can put that int into a class holding only that value:

class Integer(
val value: int
)

since Integer can be nullable, the whole int can be nullable.

[PandaH.]

oh ok, thanks!