ArrayList or mutanleListOf. Strikes me latter is better. My understanding is Arraylist specifically uses the Java implementation while mutanleListOf does not specifically use it, it tells kotlin to decide. Although if you are using JVM it will (currently) use the Java class if you are not using JVM (i.e. you are maybe doing iOS implementation) it would choose the appropriate class. So if I was planning on going to KMM in the future ArrayList would have to be changed to mutanleListOf? Would ArrrayList be preferable ever?

Usually if you don't specifically need

ArrayList

, you should stick to the more general

mutableListOf

and let Kotlin decide, as you said, KMM or not. Note that

ArrayList

is defined in common Kotlin code, so it would be available in KMM too anyway, but that's not really the point of using

mutableListOf

- it's more about generality

The only time I would use it is when interacting with a poor third party API that requires ArrayList for the types of parameters.

ArrayList has a method to explicitly reserve space for additional elements

I use

ArrayList

if I know the initial capacity.

In most cases where I know the initial capacity, I can usually build the target list out of a

map

operation or other functional operators, so I still don't need

ArrayList

. I haven't needed it directly for quite some time to be frank. That said, I also haven't needed

mutableListOf

much either.

buildList { ... }

usually covers everything that cannot be more efficiently expressed by functional operators

Thanks, everybody.

And

buildList

also allows you to add an initial capacity too.