I want to build a "2D array", and set and change elements in it. I think a mutableList does not work...

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[Martin Barth]

I want to build a "2D array", and set and change elements in it. I think a mutableList does not work well, because i cant not randomly set elements in it. It gives a index out of bound exception. Is there a autogrow option? or should i use a different data structure?

[Ole K. Øverland (Norway)]

You want to do myList.set(34,"example") and if index 34 doesn't exist, you want to grow list to this size (or larger)?

I don' think there is a list for this, but you could always make your own to do exactly what you want or make a function that check size and add null or empty value until your index

[nkiesel]

wild guess: AoC day 11. Try Array<CharArray> or Array<IntArray>

[Martin Barth]

the array works for me 🙂

[Martin Barth]

@Ole K. Øverland (Norway) you mean i need ti implmenet the interface myself? since i can not grow a mutable list myself, right?

[nkiesel]

fun toArray(l: List<String>) = l.map { it.toCharArray() }.toTypedArray(). and then use data[row][col] to access (and set) chars in that 2D

[nkiesel]

alternative is to use just a CharArray but that needs more juggling with with % to compute the correct index

[Martin Barth]

solved the advent of code task 😄