| Algorithm::CheckDigits::MBase_001(3pm) | User Contributed Perl Documentation | Algorithm::CheckDigits::MBase_001(3pm) |
NAME¶
CheckDigits::MBase_001 - compute check digits for UPC (US)
SYNOPSIS¶
use Algorithm::CheckDigits;
$rv = CheckDigits('upc');
if ($rv->is_valid('012345678905')) {
# do something
}
$cn = $rv->complete('01234567890');
# $cn = '012345678905'
$cd = $rv->checkdigit('012345678905');
# $cd = '5'
$bn = $rv->basenumber('012345678905');
# $bn = '01234567890'
DESCRIPTION¶
ALGORITHM¶
- 1.
- Add all digits in odd-numbered positions.
- 2.
- Multiply the sum from step 1 with 3.
- 3.
- Add all digits in even-numbered positions.
- 4.
- Add the product from step 2 and the sum from step 3.
- 5.
- If the sum from step 4 is 0 modulo 10, the check digit is 0. Else the check digit is 10 minus the sum from step 4 taken modulo 10.
METHODS¶
- is_valid($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>"
THANKS¶
Aaron W. West pointed me to a fault in the computing of the check digit.
SEE ALSO¶
perl, CheckDigits, www.pruefziffernberechnung.de, www.export911.com/e911/coding/upcChar.htm, www.adams1.com/pub/russadam/upccode.html, http://www.upcdatabase.com.
| 2021-11-17 | perl v5.40.0 |