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3## Copyright (C) 2017-2021 The Octave Project Developers
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5## See the file COPYRIGHT.md in the top-level directory of this
6## distribution or <https://octave.org/copyright/>.
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25
26## -*- texinfo -*-
27## @deftypefn {} {} isstring (@var{s})
28## Return true if @var{s} is a string array.
29##
30## A string array is a data type that stores strings (row vectors of
31## characters) at each element in the array.  It is distinct from character
32## arrays which are N-dimensional arrays where each element is a single 1x1
33## character.  It is also distinct from cell arrays of strings which store
34## strings at each element, but use cell indexing @samp{@{@}} to access
35## elements rather than string arrays which use ordinary array indexing
36## @samp{()}.
37##
38## Programming Note: Octave does not yet implement string arrays so this
39## function will always return false.
40## @seealso{ischar, iscellstr, isfloat, isinteger, islogical, isnumeric, isa}
41## @end deftypefn
42
43function retval = isstring (s)
44
45  if (nargin != 1)
46    print_usage ();
47  endif
48
49  retval = false;
50
51endfunction
52
53
54%!assert (isstring ([]), false)
55%!assert (isstring (1), false)
56%!assert (isstring ('a'), false)
57## FIXME: when string arrays are implemented, this should return true.
58#%!assert (isstring ("b"), true)
59%!assert (isstring ({'a'}), false)
60%!assert (isstring ({"b"}), false)
61
62%!error isstring ()
63%!error isstring ("a", "b")
64