is it possible to use extension functions in `when...

# announcements

[aaverin]

is it possible to use extension functions in when statements?

when(myObject) {
  myCustomExtensionFunctionOnMyObject -> do something
}

[Milan Hruban]

I believe you would have to use when expression without a subject (assuming the extension returns boolean)

val myObject = ...

when {
myObject.myCustomExtensionFunctionOnMyObject() -> do something
}

[aaverin]

hmm, then multiple cases do not combine

[aaverin]

like

when {
  myObject.check1() -> do1
  myObject.check2(),
  myObject.check3() -> do23
  else -> doElse
}

[aaverin]

Maybe && will work

[aaverin]

or ||

[Milan Hruban]

yes it will, but I think you meant ||

[jaqxues]

you can also define a val in when:

when (val myObj = someProp.getSth()) {
    myObj.test1() -> //...
    myObj.test2() -> //...
}

might be handy for some use cases

[jaqxues]

he wants to use it with a when

[David Eriksson]

Silly me, thanks @jaqxues