这段程序会输出什么?
kotlin
sealed interface UploadState {
data object Waiting : UploadState
data class Complete(val files: Int) : UploadState
}
fun label(state: UploadState): String = when (state) {
UploadState.Waiting -> "waiting"
is UploadState.Complete -> "${state.files} files"
}
fun main() {
println(label(UploadState.Complete(3)))
}