---
name: "Algorithm::CheckDigits::M11_003"
section: "3pm"
platform: "linux"
package: "libalgorithm-checkdigits-perl"
version: "1.3.6-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Algorithm::CheckDigits::M11_003"
---

# Algorithm::CheckDigits::M11\_003(3pm)

compute check digits for PKZ (GDR)

## NAME

CheckDigits::M11\_003 - compute check digits for PKZ (GDR)

## SYNOPSIS

```
  use Algorithm::CheckDigits;
  $pkz = CheckDigits('pkz');
  if ($pkz->is_valid('150765400354')) {
        # do something
  }
  $cn = $pkz->complete('15076540035');
  # $cn = '150765400354'
  $cd = $pkz->checkdigit('150765400354');
  # $cd = '4'
  $bn = $pkz->basenumber('150765400354');
  # $bn = '150765400354'
```

## DESCRIPTION

### ALGORITHM

- 1\.

  The checkdigit is set to 0.

- 2\.

  From right to left the digits are weighted (multiplied) with 2,4,8,5,10,9,7,3,6,1,2,4.

- 3\.

  The products are added.

- 4\.

  The sum of step 3 is taken modulo 11.

- 5\.

  The value of step 4 is added to a multiple (0..9) of the weight of the checkdigit (2).

- 6\.

  The sum of step 5 is taken modulo 11.

- 7\.

  The checkdigit is the multiple of the weight of the checkdigit where the value of step 6 equals 10.

- 8\.

  If there can't be reached a value of 10 in step 6, the number cannot be taken as a PKZ.

To validate a PKZ apply steps 2 to 4 to the complete number.

### 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>"`

## SEE ALSO

perl, CheckDigits, *www.pruefziffernberechnung.de*.