Java assigning a two-dimensional arrayto a three-dimensional array

Question

I have the following code which seems to compile:

int[] arr = {1, 2};
int[][] arr2 = {arr, {1, 2}, arr};
int[][][] arr3 = {arr2};

Could you please explain why the last statement works? Don't we assign a two-dimensional array to a three-dimensional array here?

Thanks

Suresh Atta · Accepted Answer · 2017-02-22 12:56:28Z

2

Don't we assign a two-dimensional array to a three-dimensional array here?

You are correct if you do this

   int[][][] arr3 = arr2;

But what you are doing here int[][][] arr3 = {arr2}; is not assigning. You are creating array with an element inside it.

Adding an element and assigning the references are 2 different things.

That works because in your array called arr3 you have a 2D array at row zero and column zero which is fine.

Inshort

int[][][] arr3 = {arr2};

is equals to

int[][][] arr3 = new int[10][10][10];
arr3[0] = arr2;

answered Feb 22, 2017 at 12:48

Suresh Atta

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