How to store subList operation on an ArrayList in another ArrayList in Kotlin?

Question

I am using Kotlin REPL in IntelliJ Idea

I have an ArrayList.

val myArrayList: ArrayList<String?> = arrayListOf("pig", null, "cow", "chicken", "chicken", "duck", "turkey", "pig", null, null, "turkey", "pig")

the operation

myArrayList.subList(2, 3)

gives me the output:

res5: kotlin.collections.MutableList<kotlin.String?> = [cow]

But the operation

val myArraySubList: ArrayList<String?> = myArrayList.subList(2, 3)

gives me the error:

error: type mismatch: inferred type is MutableList<String?> but kotlin.collections.ArrayList<String?> /* = java.util.ArrayList<String?> */ was expected
val myArraySubList: ArrayList<String?> = myArrayList.subList(2, 3)
                                         ^

So, here how can I store the result of a subList operation on an ArrayList in another ArrayList?

Answer 1

ArrayList(myArrayList.subList(2, 3))

using this constructor:

<init>(elements: Collection<E>)

Creates an ArrayList filled from the elements collection.

But consider whether you actually need it: using ArrayList explicitly instead of MutableList is very rarely useful.