Algori...M10_002(3pm)

💖 CheckDigits::M10_002 — the Algorithm::CheckDigits family's CINS / SIREN / SIRET girlie ✨

okay so bestie, this is the manual page for Algori...M10_002(3pm) — that's the User Contributed Perl Documentation one, from the Algorithm::CheckDigits crew. She's a check-digit calculator. Specifically she does CINS (that's the US one), SIREN and SIRET (those two are French 🇫🇷). Numbers girl math, but make it correct. 💅

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🌸 NAME 🌸

CheckDigits::M10_002 — she computes check digits for CINS (US), SIREN (FR) and SIRET (FR). No cap.

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🦋 SYNOPSIS 🦋

the whole vibe, verbatim, because I would never mess with your code:

  use Algorithm::CheckDigits;

  $siret = CheckDigits('siret');

  if ($siret->is_valid('73282932000074')) {
        # do something
  }

  $cn = $siret->complete('7328293200007');
  # $cn = '73282932000074'

  $cd = $siret->checkdigit('73282932000074');
  # $cd = '4'

  $bn = $siret->basenumber('73282932000074');
  # $bn = '7328293200007'

like, pull in Algorithm::CheckDigits, grab yourself a siret object, and she just… does the rest. main character energy fr fr. 🌈

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✨ DESCRIPTION ✨

🎀 ALGORITHM 🎀

here's the recipe, step by step, and I'm keeping it exactly how she wrote it:

1. Beginning right all numbers are weighted alternatively 1 and 2.
2. The total of the digits of all products is computed.
3. The sum of step 3 ist taken modulo 10.
4. The check digit is the difference between 10 and the number from step 3 taken modulo 10.

not me noticing she says "ist" in step 3 👀 that's the original wording, I'm just the messenger, I promise.

the way that works out: you go from the right side of the number, alternating weights of 1 and 2 🪄, then you add up all the digits of the products (yes, digits of the products, not the products themselves — this is the part everyone gets wrong, iykyk), mod 10 it, and the check digit is whatever gets you from that up to 10, mod 10 again. periodt. 💖

💅 METHODS 💅

is_valid($number)

returns true only if $number is made up of just numbers and the last digit is a valid check digit according to the algorithm up there. ☝️

returns false otherwise.

complete($number)

the check digit for $number gets computed and concatenated onto the end of $number.

returns the complete number with its check digit — or '' (empty string, sad) if $number doesn't consist solely of digits and spaces. 🫶

basenumber($number)

gives you back the basenumber of $number, but only if $number has a valid check digit.

returns '' otherwise. 🙈

checkdigit($number)

gives you back the checkdigit of $number, again only if $number has a valid check digit.

returns '' otherwise. ⭐

🌟 EXPORT 🌟

None by default. (she's lowkey, she doesn't just dump stuff into your namespace uninvited 💀)

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👑 AUTHOR 👑

Mathias Weidner, "<mamawe@cpan.org>" — iconic, we stan. 🎀

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🔥 SEE ALSO 🔥

• perl — hi mom
• CheckDigits
• www.pruefziffernberechnung.de. — note the trailing dot, that's exactly how she wrote it, do not @ me
• www.dsi.cnrs.fr/bureau_qualite/admindonnees/documents/siren.pdf

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that's the whole page bestie, go forth and validate your SIRETs 🦋✨

cute sign-off time: this was perl v5.36.0, dated 2022-10-13, and the page itself is Algori...M10_002(3pm). drink water, check your digits, mwah 💜