ArrayQ

ArrayQ[expr]
gives True if expr is a full array or a SparseArray object, and gives False otherwise.

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.

DetailsDetails

  • 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.

ExamplesExamplesopen allclose all

Basic Examples (2)Basic Examples (2)

A vector of numbers is a full array:

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A vector in which one element is itself a list is not a full array:

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A ragged collection of nested lists is not a full array:

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