Can I have an `enum class` with an other value Aka ```enum c

Question

Can I have an `enum class` with an other value Aka ```enum class Status val value Int Present 2 Absent 1 Error value ```

Joffrey · Answer

Do you mean that you would like `Error` to support different values depending on the case

reactormonk · Answer

Or rather all other values I m using it for status codes coming from a proprietary jar so I have a few hints on what might come out of there

reactormonk · Answer

I know these two values but any others might occur

Joffrey · Answer

Enums are not meant for that Each enum value entry in the list has only one instance so you cannot have 2 instances of `Status Error` with different values So I would say you have 2 main options 1 if you don t really need the error code the `value` property you may keep an enum but remove the `value` property just map your error codes to one of the 3 enum states without storing the error code in the enum value Note that in Kotlin enums don t need to be associated with a number or anything maybe that s the missing piece of the puzzle for you 2 if you do need the code it means you want different instances of those enum values with different codes In that case you cannot use an enum but you can use a `sealed class` instead

Joffrey · Answer

Option 1 could look like this ```enum class Status Present Absent Error companion object fun fromStatusCode code Int = when code 1 gt Absent 2 gt Present else gt Error ``` I m assuming 1 and 2 here are probably not what you want assuming you had assigned numbers to the enum entries just because you thought you had to But you could map your actual status codes here

Joffrey · Answer

I can elaborate on option 2 if that s what you need but I ll wait for your answer first

reactormonk · Answer

Kinda got to ```sealed class CardStatus val value Int class CardPresent CardStatus 2 class CardAbsent CardStatus 1 class CardError value Int CardStatus value fun Int toCardStatus CardStatus return when this 2 gt CardPresent 1 gt CardAbsent else gt CardError this ```

reactormonk · Answer

slack enter always trips me up

reactormonk · Answer

So I can keep the status code around for the error message in the future

reactormonk · Answer

companion object would be the more conventional way to go about it

reactormonk · Answer

switched it over thanks for the help

Joffrey · Answer

gt companion object would be the more conventional way to go about it Not necessarily but it depends on where you put this extension on `Int` Because `Int` is a very common type there is a chance this will pollute auto completion in your project hence why I would personally tend to favor `CardStatus fromCode Int ` over extensions on `Int` if this is a public function like in your case if it s a private function it s quite ok

Joffrey · Answer

2 minor points about your sealed class 1 Because `CardPresent` and `CardAbsent` always hold the same value they can be `object`s instead of classes you don t need new instances every time 2 If the naming makes sense with nesting you can nest your sealed class s subclasses inside the sealed class so they are referred to with the `SealedParent Child` syntax In your case this would read `CardStatus Present` `CardStatus Absent` `CardStatus Error` but that s a matter of taste

reactormonk · Answer

Does mess a tiny bit with the `toString` in terms of clarity but then you should add enough context smile

Joffrey · Answer

If you care about `toString ` it may be worth making `CardError` a `data class` then wink

reactormonk · Answer

Yup just did ^^