Hi maybe a stupid question but I never thought about that before. When I define a `mutableListOf<...

# android

[Lilly]

Hi maybe a stupid question but I never thought about that before. When I define a mutableListOf<String> and pass this to a consuming function, should I convert this list explicitly to List<String> with toList() to have this list immutable or is it enough to define the parameter as List<String> like:

fun consumingList(list: List<String>)

But then I'm asking if it's really an immutable list... I could still cast it to a mutable List again, not?

[Matt Rea]

Defining the parameter like that is fine. It’s all mutable under the hood. List just exposes less than MutableList. And like you mentioned, you can use toList() or toMutableList() to convert between them

[ursus]

depends on how much you trust your consumers, it might be okay just to cast

[Lilly]

ok, Thanks guys :)