How should I handle a value that should be ignored...

# announcements

[steenooo]

How should I handle a value that should be ignored in a when statement?
in fx this situation

enum Foo { FOO, BAR, FOOBAR }

val foo = ...
when(foo) {
  FOO -> sayFoo()
  BAR -> sayBar()
  FOOBAR -> do nothing
}

[Shawn]

Unit should work, I’m pretty sure

[Luke Rohde]

unit works, but also if you are returning nothing you can also simply omit the FOOBAR clause

[Daniel]

when(foo) {
  FOO -> sayFoo()
  BAR -> sayBar()
}

or

when(foo) {
  FOO -> sayFoo()
  BAR -> sayBar()
  FOOBAR -> Unit
}

[Kashif]

don’t add FOOBAR in when

[Shawn]

iirc the IDE warns even if you aren’t using when as an expression and miss an enum value

[Shawn]

or, at least, maybe it used to

[steenooo]

oki, thanks! Must've been a mistake when I was trying out what to do, because I remember the IDE giving an error about missing values. but it seems to work fine omitting FOOBAR now.. weird.. thanks!

[Kashif]

👍

[Luke Rohde]

you will get an error if you do something like

val ret = when(foo) {
  FOO -> sayFoo()
  BAR -> sayBar()
}

[Luke Rohde]

statement doesn’t require exhaustive coverage, expression does

[steenooo]

Yes. that must've been it

[Casey Brooks]

You can also use an empty code block, which I find a bit more understandable

when(foo) {
    FooBar.FOO -> sayFoo()
    FooBar.BAR -> sayBar()
    FooBar.FOOBAR -> {}
}