---
name: "Algorithm::CheckDigits::M10_010"
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::M10_010"
---

# Algorithm::CheckDigits::M10\_010(3pm)

compute check digits for Postscheckkonti (CH)

## NAME

CheckDigits::M10\_010 - compute check digits for Postscheckkonti (CH)

## SYNOPSIS

```
  use Algorithm::CheckDigits;
  $pck = CheckDigits('postcheckkonti');
  if ($pck->is_valid('85-12345678-7')) {
        # do something
  }
  $cn = $pck->complete('85-12345678');
  # $cn = '85-12345678-7'
  $cd = $pck->checkdigit('85-12345678-7');
  # $cd = '7'
  $bn = $pck->basenumber('85-12345678-7');
  # $bn = '85-12345678'
```

## DESCRIPTION

### ALGORITHM

- 1\.

  The sequence of digits is processed left to right. For the first digit we assume a carry forward of 0.

- 2\.

  For each digit d(i) the carry forward cf(i) is the digit at the the position p in the sequence ( 0, 9, 4, 6, 8, 2, 7, 1, 3, 5 ), where p is (d(i) + cf(i-1)) modulo 10.

- 3\.

  The check digit is the difference of the sum from step 3 to the next multiple of 10.

### 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*.