Atoms, lists, and tables are all arrays. All nouns in J are arrays. Atoms have 0 dimensions, lists have 1 dimension, and tables have 2 dimensions. This extends to higher dimension arrays.
The primitive $, discussed earlier with lists and tables also works with higher dimension arrays.
2 3 4 $ i. 24 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
The above is a 3-dimensional array. The blank line indicates the break between the 1st dimension and the 2nd and 3rd.
b =. 2 3 4 $ 'abcdef' $ b 2 3 4
The monad i. also works with higher dimension arrays.
i. 2 3 4 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
The J terms atom, list, and table are analogous to the math terms of scalar, vector, and matrix.