CheckDigits::MXX_003(3pm)				User Contributed Perl Documentation				 CheckDigits::MXX_003(3pm)

NAME

       CheckDigits::MXX_003 - compute check digits for DEM

SYNOPSIS

	 use Algorithm::CheckDigits;

	 $dem = CheckDigits('dem');

	 if ($dem->is_valid('GD0645027K1')) {
	       # do something
	 }

	 $cn = $dem->complete('GD0645027K');
	 # $cn = 'GD0645027K1'

	 $cd = $dem->checkdigit('GD0645027K1');
	 # $cd = '1'

	 $bn = $dem->basenumber('GD0645027K1');
	 # $bn = 'GD0645027K'

DESCRIPTION

   ALGORITHM
       The algorithm is a variation of the Verhoeff scheme.

       0   All letters are changed to numbers.

       1   All digits are permutated according to a permutation table.

       2   The permutated digits are combined using a dieeder table. The first with the second, the result with the third, this result with the
	   fourth and so on.

       3   The result of the last combination in the dieeder table is in such a way combined that the result is 0 (zero). The number used for this
	   combination is the checksum.

       For details look at the source.

   METHODS
       is_valid($number)
	   Returns true only if $number consists solely of numbers and the last digit is a valid check digit according to the algorithm given
	   above.

	   Returns false otherwise,

       complete($number)
	   The check digit for $number is computed and concatenated to the end of $number.

	   Returns the complete number with check digit or '' if $number does not consist solely of digits and spaces.

       basenumber($number)
	   Returns the basenumber of $number if $number has a valid check digit.

	   Return '' otherwise.

       checkdigit($number)
	   Returns the checkdigit of $number if $number has a valid check digit.

	   Return '' otherwise.

   EXPORT
       None by default.

AUTHOR

       Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>

THANKS

SEE ALSO

       perl, CheckDigits, www.pruefziffernberechnung.de,

perl v5.10.0							    2008-05-17						 CheckDigits::MXX_003(3pm)