#### A.1.4 Cell Arrays in Oct-Files

Octave's cell type is equally accessible within oct-files. A cell array is just an array of `octave_value`s, and so each element of the cell array can then be treated just like any other `octave_value`. A simple example is

         #include <octave/oct.h>
         #include <octave/Cell.h>

         DEFUN_DLD (celldemo, args, , "Cell Demo")
         {
           octave_value_list retval;
           int nargin = args.length ();

           if (nargin != 1)
             print_usage ();
           else
             {
               Cell c = args (0).cell_value ();
               if (! error_state)
                 for (octave_idx_type i = 0; i < c.nelem (); i++)
                   retval(i) = c.elem (i);
             }

           return retval;
         }

Note that cell arrays are used less often in standard oct-files and so the `Cell.h` header file must be explicitly included. The rest of this example extracts the `octave_value`s one by one from the cell array and returns be as individual return arguments. For example consider

         [b1, b2, b3] = celldemo ({1, [1, 2], "test"})
         ⇒
         b1 =  1
         b2 =

            1   2

         b3 = test