NAME

CheckDigits::M11_002 - compute check digits for PZN (DE)

SYNOPSIS

  use Algorithm::CheckDigits;

  $pzn = CheckDigits('pzn');

  if ($pzn->is_valid('4877800')) {
        # do something
  }

  $cn = $pzn->complete('487780');
  # $cn = '4877800'

  $cd = $pzn->checkdigit('4877800');
  # $cd = '0'

  $bn = $pzn->basenumber('4877800');
  # $bn = '487780'

DESCRIPTION

ALGORITHM

1.: From left to right beginning with the first position all digits are multiplied with 2,3,4,...
2.: The sum of all products is computed.
3.: The checkdigit ist the sum of step 2 taken modulo 11.
4.: If the checkdigit is '10' the whole number is not taken as a PZN.

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, "<mamawe@cpan.org>"