Wolfram Mathematica Documentation Center
DOCUMENTATION CENTER SEARCH
Mathematica >
Built-in Mathematica SymbolTutorials »|See Also »|More About »

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.
  • 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.
EXAMPLESCLOSE ALL
Basic Examples   (2)
A vector of numbers is a full array:
In[1]:=
Click for copyable input
Out[1]=
A vector in which one element is itself a list is not a full array:
In[2]:=
Click for copyable input
Out[2]=
 
A ragged collection of nested lists is not a full array:
In[1]:=
Click for copyable input
Out[1]=
In[2]:=
Click for copyable input
Out[2]=
New in 5
Ask a question about this page  |  Suggest an improvement  |  Leave a message for the team