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##
## Copyright (C) 1998-2024 The Octave Project Developers
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## See the file COPYRIGHT.md in the top-level directory of this
## distribution or <https://octave.org/copyright/>.
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########################################################################

## -*- texinfo -*-
## @deftypefn {} {@var{tf} =} isletter (@var{s})
## Return a logical array which is true where the elements of @var{s}
## are letters and false where they are not.
##
## This is an alias for the @code{isalpha} function.
## @seealso{isalpha, isdigit, ispunct, isspace, iscntrl, isalnum}
## @end deftypefn

function tf = isletter (s)

  if (nargin < 1)
    print_usage ();
  endif

  tf = isalpha (s);

endfunction


%!error <Invalid call> isletter ()
%!error isletter ("a", "b")