Hello, I have a quick question. Does anyone knows why Kotlin ArrayDeque does not have offerLast or o...

# getting-started

[Haram Kwon]

Hello, I have a quick question.
Does anyone knows why Kotlin ArrayDeque does not have offerLast or offer series functions? (while Java ArrayDeque java has OfferLast)
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-array-deque/
https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/ArrayDeque.html

[Adam S]

There’s addLast() https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-array-deque/add-last.html - does that do what you need?

[Haram Kwon]

@Adam S not quite...

[Haram Kwon]

example, removeLast() throws exception when there is no element, while pollLast return null when there is no object 🧐

[Adam S]

based on this answer https://stackoverflow.com/q/29092043/4161471 I would infer there’s no difference between addLast() and offerLast() even in the Java version of ArrayDeque

[Adam S]

removeLast() is equivalent to removeLast(), while pollLast() would be equivalent to removeLastOrNull()

[Haram Kwon]

oh thanks. Do you know why this line is throwing error?

[Haram Kwon]

I thought ArrayDeque implements Deque 🧐

[Adam S]

it doesn’t https://github.com/JetBrains/kotlin/blob/924c28507067cbfbf78a6509ea89eabe496e34ca/libraries/stdlib/src/kotlin/collections/ArrayDeque.kt#L18

[Adam S]

I would guess because Deque is JVM only

[Haram Kwon]

thanks!!

[Adam S]

you’re welcome :)