BUILT-IN MATHEMATICA SYMBOL
ArrayQ
ArrayQ[expr, patt]
requires expr to be a full array with a depth that matches the pattern patt.
ArrayQ[expr, patt, test]
requires also that test yield True when applied to each of the array elements in expr.
- In a full array all parts at a particular level must be lists of the same length.
- ArrayQ[expr, 1|2] tests whether expr is either a vector or a matrix.
- ArrayQ[expr, _, NumberQ] tests whether expr is a numerical array at all levels.
A vector of numbers is a full array:
| Out[1]= |  |
A vector in which one element is itself a list is not a full array:
| Out[2]= |  |
A ragged collection of nested lists is not a full array:
| Out[1]= |  |
| Out[2]= |  |
New in 5
