SYNOPSIS
use Algorithm::CheckDigits;
$vat = CheckDigits('ustid_at');
if ($vat->is_valid('U13585627')) {
# do something
}
$cn = $vat->complete('U1358562');
# $cn = 'U13585627'
$cd = $vat->checkdigit('U13585627');
# $cd = '7'
$bn = $vat->basenumber('U13585627');
# $bn = 'U1358562'
DESCRIPTION
ALGORITHM
- 1.
- Beginning right all numbers before the check digit are weighted alternatively 1 and 2.
- 2.
- The total of the digits of all products is computed and then subtracted from 96.
- 3.
- The check digit is the sum of step 3 taken modulo 10.
METHODS
- is_valid($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.