How to make an array of arrays in kotlin?

Question

I have an array of userIDs, which contains specific users from a certain group.

{userID1,userID2}

val userIDArrayList: ArrayList<String> = ArrayList()
    userIDArrayList.add(userID1)
    userIDArrayList.add(userID2)

I want to make a master array which contains several different user arrays.

[{userID1, userID2}, {userID3, userID4}]

How can I do that in kotlin?

Just one note, these are Lists not Arrays. It's called ArrayList because it's a list implemented with arrays, but it's not equivalent to an array. — gpunto
– gpunto, Commented Jun 4, 2022 at 9:58

Sasi Kumar · Accepted Answer · 2022-06-04 08:03:13Z

1

mutableListOf(mutableListOf("yourobject"),mutableListOf("yourobject"))

or

val myList = mutableListOf<MutableList<yourobject>>()

answered Jun 4, 2022 at 8:03

Sasi Kumar

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Comments

Jolan DAUMAS · Accepted Answer · 2022-06-04 08:03:22Z

0

First, declare the master array which will contains other arrays

    val masterList = mutableListOf<List<String>>()

Secondly, declare the arrays which will be nested. Assuming userID1, userID2, userID3, userID4 are declared somewhere

    val subList1 = listOf(userID1,userID2)
    val subList2 = listOf(userID3,userID4)

Finally, add the sublists to the master

    masterList.add(subList1)
    masterList.add(subList2)

Of course you can do all of this with only one line during masterList instantiation

    val masterList = mutableListOf<List<String>>(
        listOf(userID1,userID2),
        listOf(userID3,userID4)
    )

answered Jun 4, 2022 at 8:03

Jolan DAUMAS

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Can we send the mutable list via an intent to another activity?