≡ Depth

One-argument form  See also two-argument form Match

Depth is used to indicate the level of nesting. For a simple scalar, depth is 0. For other arrays, the depth of the array is 1+ the depth of the item of maximum depth in the array.

             ≡4                      (Depth of a scalar is 0)
       0
             ≡⍳4                     (Depth of a vector is 1)
       1
             ≡2 2⍴⍳6                 (Depth of a matrix is 1)
       1
             ≡'ABC' 1 2 3 (23 55)    (Maximum depth is 1+ depth of a vector)
       2
             'ABC' (2 4⍴('ABC' 2 3 'K'))
       ABC  ABC 2 3 K                (Maximum depth object within the array is
            ABC 2 3 K                 2 - a matrix)
             ≡'ABC' (2 4⍴('ABC' 2 3 'K'))
       3                             (Overall depth is thus 3)

See also ⍴ (shape) to enquire about the shape of an array.