---
name: "Algorithm::CheckDigits::MXX_006"
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::MXX_006"
---

# Algorithm::CheckDigits::MXX\_006(3pm)

compute check digits with Verhoeff scheme

## NAME

CheckDigits::MXX\_006 - compute check digits with Verhoeff scheme

## SYNOPSIS

```
  use Algorithm::CheckDigits;
  $verhoeff = CheckDigits('verhoeff');
  if ($verhoeff->is_valid('14567894')) {
        # do something
  }
  $cn = $verhoeff->complete('1456789');
  # $cn = '14567894'
  $cd = $verhoeff->checkdigit('14567894');
  # $cd = '4'
  $bn = $verhoeff->basenumber('14567894');
  # $bn = '1456789'
```

## DESCRIPTION

### ALGORITHM

- 1\.

  Right to left 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.

- 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>"`

## THANKS

Jonathan Peters wrote Algorithm::Verhoeff from which I took the routine to compute the checkdigits.

## SEE ALSO

perl, CheckDigits, \<http://www.cs.utsa.edu/~wagner/laws/verhoeff.html\>, \<http://www.cs.nmsu.edu/~cssem/Dickcheckdoc.pdf\>