Algorithm::CheckDigits::M11_008(3)

NAME
CheckDigits::M11_008 - compute check digits for VAT Registration Number (DK)

SYNOPSIS
  use Algorithm::CheckDigits;

  $ustid = CheckDigits('ustid_dk');

  if ($ustid->is_valid('13585628')) {
        # do something
  }

  $cn = $ustid->complete('1358562');
  # $cn = '13585628'

  $cd = $ustid->checkdigit('13585628');
  # $cd = '8'

  $bn = $ustid->basenumber('13585628');
  # $bn = '1358562';

DESCRIPTION

  ALGORITHM

1.  Beginning left every digit is weighted with 2, 7, 6, 5, 4, 3, 2, 1

2.  The weighted digits are added.

3.  The sum from step 2 is taken modulo 11.

4.  The number is valid if the sum from step 3 is zero (0).

  METHODS

is_valid($number)
    Returns true only if $number consists solely of numbers and the sum computed according to the algorithm given above is 0.

    Returns false otherwise,

complete($number)
    Returns $number if $number is valid according to the algorithm given above.

    Return '' otherwise.

basenumber($number)
    Returns $number if $number is valid according to the algorithm given above.

    Return '' otherwise.

checkdigit($number)
    Returns '' if $number is valid.

    Return undef otherwise.

  EXPORT
None by default.

AUTHOR
Mathias Weidner, "<mamawe@cpan.org>"

SEE ALSO
perl, CheckDigits, www.pruefziffernberechnung.de,