---
name: "Algorithm::CheckDigits::M11_015"
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_015"
---

# Algorithm::CheckDigits::M11\_015(3pm)

compute check digits for ESR5 (CH)

## NAME

CheckDigits::M11\_015 - compute check digits for ESR5 (CH)

## SYNOPSIS

```
  use Algorithm::CheckDigits;
  $ustid = CheckDigits('esr5_ch');
  if ($ustid->is_valid('050001000012000 241170032660178 10304')) {
        # do something
  }
  $cn = $ustid->complete('0001000012000 241170032660178 10304');
  # $cn = '050001000012000 241170032660178 10304'
  $cd = $ustid->checkdigit('0001000012000 241170032660178 10304');
  # $cd = '05'
  $bn = $ustid->basenumber('050001000012000 241170032660178 10304');
  # $bn = '0001000012000 241170032660178 10304';
```

## DESCRIPTION

### ALGORITHM

- 1\.

  Beginning right all digits are weighted with the repeating sequence 2, 3, 4, 5, 6, 7.

- 2\.

  The weighted digits are added.

- 3\.

  The sum from step 2 is taken modulo 11.

- 4\.

  The checkdigit is 11 minus the sum from step 3. If the difference is 11, the checkdigit is 00.

### METHODS

- is\_valid($number)

  Returns true only if `$number` consists solely of numbers (with or without space between them) and the first two digits are valid check digits according to the algorithm given above.

  Returns false otherwise,

- complete($number)

  The check digit for `$number` is computed and inserted before the `$number`.

  Returns the complete number with check digit or '' if `$number` does not consist solely of digits, spaces.

- basenumber($number)

  Returns the basenumber of `$number` if `$number` has a valid check digit.

  Return '' otherwise.

- checkdigit($number)

  Returns the check digits of `$number` if `$number` has valid check digits.

  Return '' otherwise.

### EXPORT

None by default.

## AUTHOR

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

## SEE ALSO

perl, CheckDigits, *http://www.pruefziffernberechnung.de/E/Einzahlungsschein-CH.shtml* (german), *http://www.sic.ch/de/dl\_tkicch\_dta.pdf*, page 52 (german)