Are lists in Kotlin random access data structure a...

# getting-started

[thhh]

Are lists in Kotlin random access data structure and is it the same case for the list in Java? Also, how does one verify if the list in random-access collection or not practically through code sample?

[Roukanken]

List<T> can't be said to be an random access structure

There are several different implementations of this interface, notably ArrayList<T> (random access) and LinkedList<T> (NOT random access - `get(i)`/`[i]` are linear in time for linked list)

[Michael Böiers]

Kotlin provides the interface RandomAccess which you can use to check whether a list supports fast index based access.

[ephemient]

(same as Java)

[ephemient]

LinkedList is not random access, however there is very little reason to use it

[Michael Böiers]

I’ve always seen the use of LinkedList as a code smell for premature optimization 🙂

[ephemient]

"listOf()", the return value of ".map{}", etc. return a random access list

[ephemient]

so unless you're explicitly creating a linked list your list is almost certainly random access

[nanodeath]

agreed that LinkedList is a low-key code smell. it's useful for queue-type things where you're popping things off the front a lot, but often there are better alternatives (like ArrayDeque)