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.