The call type(A, array) checks to see if A is an array.  It will return true if A is an array, and false otherwise.  It does not check the entries of A. See the information under array for a description of the array data structure and how to create arrays.

The optional argument(s) must be either integers, ranges, names or a type.  They are used to specify the kind of array and the type of the entries of the array.

If x_i is an integer it specifies the number of dimensions of the array A.  For example, 'array'(2) would specify a 2-D array.

If $x_1,x_2,...,x_n$ are ranges, they specify the array bounds (and implicitly the dimension) of the array A.  For example, 'array'(1..2,1..posint) would specify a 2-D array with exactly two rows and one or more columns.

If $x_1,...,x_n$ are names of indexing functions, they specify the kind of array.  For example, 'array'(symmetric) specifies a symmetric array, that is, an array with the symmetric indexing function.

If x is a type, it specifies the type of the entries of the array. For example, 'array'(numeric) specifies an array with numerical entries. See the information under type for a description of available types in Maple.  Note, if any entries of A are undefined, then their type will not be checked.  Thus if A is an array which has no defined elements, then type(A, 'array'(x)) will always return true.

It is necessary to surround the word array with quotes (') when using this function in the second form.  This prevents invocation of the array function, which is used to create arrays.

Note: The array command has been superseded by Array.

$A≔\mathrm{array}\left(1..2\,1..2\,\left[\left[1\,3\right]\,\left[\frac{1}{2}\,5\right]\right]\right)$

$A≔\left[\begin{array}{cc}1& 3\\ \frac{1}{2}& 5\end{array}\right]$

$\mathrm{type}\left(A\,'\mathrm{array}'\left(\mathrm{rational}\right)\right)$

$\mathrm{true}$

$\mathrm{type}\left(A\,'\mathrm{array}'\left(\mathrm{integer}\right)\right)$

$\mathrm{false}$

$\mathrm{type}\left(A\,'\mathrm{array}'\left(2\right)\right)$

$\mathrm{true}$

$\mathrm{type}\left(A\,'\mathrm{array}'\left(1..2\,1..2\right)\right)$

$\mathrm{true}$

$\mathrm{type}\left(A\,'\mathrm{array}'\left(1..2\right)\right)$

$\mathrm{false}$

$B≔\mathrm{array}\left(1..3\,\left[x^2+5\,x^3-x\,x+1\right]\right)$

$B≔\left[\begin{array}{ccc}{x}^2+5& x^3-x& x+1\end{array}\right]$

$\mathrm{type}\left(B\,'\mathrm{array}'\left(\mathrm{polynom}\right)\right)$

$\mathrm{true}$

$\mathrm{type}\left(B\,'\mathrm{array}'\left('\mathrm{polynom}'\left(\mathrm{integer}\,x\right)\right)\right)$

$\mathrm{true}$

$C≔\mathrm{array}\left(0..2\,2..4\,\mathrm{symmetric}\right)$

$C≔array\left(\mathrm{symmetric}\,0..2\,2..4\,\left[\left(0\,2\right)={\mathrm{`?`}}_{0,2}\,\left(0\,3\right)={\mathrm{`?`}}_{0,3}\,\left(0\,4\right)={\mathrm{`?`}}_{0,4}\,\left(1\,2\right)={\mathrm{`?`}}_{1,2}\,\left(1\,3\right)={\mathrm{`?`}}_{1,3}\,\left(1\,4\right)={\mathrm{`?`}}_{1,4}\,\left(2\,2\right)={\mathrm{`?`}}_{2,2}\,\left(2\,3\right)={\mathrm{`?`}}_{2,3}\,\left(2\,4\right)={\mathrm{`?`}}_{2,4}\right]\right)$

$\mathrm{type}\left(C\,'\mathrm{array}'\left(2\,\mathrm{symmetric}\right)\right)$

$\mathrm{true}$

$\mathrm{type}\left(C\,'\mathrm{array}'\left(1..2\,1..2\right)\right)$

$\mathrm{false}$

$\mathrm{type}\left(C\,'\mathrm{array}'\left(0..\mathrm{posint}\,\mathrm{integer}..\mathrm{integer}\,\mathrm{symmetric}\right)\right)$

$\mathrm{true}$