How to initialize 2D arraylist using 2D array?

Question

I have this array

int[][] currGrid = {{1,1},{1,2},{2,2}};

And this array is static so I want to create 2D arraylist using the same elements. Is there any way to create the arraylist for same in a single line without using add in Java?

Answer 1

It's unclear to me whether you meant you want to convert this given 2D array to a 2D list, or wether you meant to just create a new list with these values as a one-liner.

If you meant the former, you could stream the array and then stream each of its elements, and collect them:

List<List<Integer>> currGridList = 
    Arrays.stream(currGrid)
          .map(g -> Arrays.stream(g).boxed().collect(Collectors.toList()))
          .collect(Collectors.toList());

If you meant the latter, you could use List.of :

List<List<Integer>> currGridList = List.of(List.of(1, 1), List.of(1, 2), List.of(2, 2));