Why we cannot put' , ' after the bracket {2,3,4} and {2,3}?

Question

int[][][] test = {
{
{1, -2, 3},
{2, 3, 4}
},
{
{-4, -5, 6, 9},
{1},
{2, 3}
}
};

// for..each loop to iterate through elements of 3d array
for (int[][] array2D: test) {
for (int[] array1D: array2D) {
for(int item: array1D) {
System.out.println(item);
}
}
}
}
}

But in 2D array, they put ',' before it end

Answer 1

Putting camma there means "still there another array left.
But for your, those are the last arrays {} so you should not put for last one...

Answer 2

Ouhh I understand. Thanks!