SYNOPSIS
use Algorithm::CheckDigits;
$ustid = CheckDigits('ustid_dk');
if ($ustid->is_valid('13585628')) {
# do something
}
$cn = $ustid->complete('1358562');
# $cn = '13585628'
$cd = $ustid->checkdigit('13585628');
# $cd = '8'
$bn = $ustid->basenumber('13585628');
# $bn = '1358562';
DESCRIPTION
ALGORITHM
- 1.
- Beginning left every digit is weighted with 2, 7, 6, 5, 4, 3, 2, 1
- 2.
- The weighted digits are added.
- 3.
- The sum from step 2 is taken modulo 11.
- 4.
- The number is valid if the sum from step 3 is zero (0).
METHODS
- is_valid($number)
-
Returns true only if $number consists solely of numbers and hyphens
and the two digits in the middle
are valid check digits according to the algorithm given above.
Returns false otherwise,
- complete($number)
-
The check digit for $number is computed and inserted into the
middle of $number.
Returns the complete number with check digit or '' if $number does not consist solely of digits, hyphens and spaces.
- basenumber($number)
-
Returns the basenumber of $number if $number has a valid check
digit.
Return '' otherwise.
- checkdigit($number)
-
Returns '' if $number is valid.
Return undef otherwise.