Question

I’m having an issue with finding some data I have put into my multidimensional arraylist. I basically have an arraylist full of arraylists…

ArrayList<ArrayList<Integer>> array = new ArrayList<ArrayList<Integer>>();

So now I want to use indexOf to find the arraylist that contains specific data because I’m comparing it to other data in the same arraylist.

For example, I know I can use a for loop to find this data —

for (i = 0; i < array.size(); i++)
{
    if (array.get(a).get(0) == array.get(i).get(0))
        //then do something
}

But I thought it’d be easier to use indexOf or lastindexOf. Does anyone know the correct way I would use it? I’m thinking it’s something like

array.indexOf(array.get(????).get(0))

but I’m not sure 🙁

Answer 1

Unfortunately this is not possible. More than that

array.indexOf(array.get(????).get(0))

is incorrect, since array.get(????).get(0) would be an Integer and array is an ArrayList of ArrayLists, not Integers.