SYNOPSIS
use Algorithm::CheckDigits;
$betrnr = CheckDigits('betriebsnummer');
if ($betrnr->is_valid('73282932000074')) {
# do something
}
$cn = $betrnr->complete('7328293200007');
# $cn = '73282932000074'
$cd = $betrnr->checkdigit('73282932000074');
# $cd = '4'
$bn = $betrnr->basenumber('73282932000074');
# $bn = '7328293200007'
DESCRIPTION
ALGORITHM
- 1.
- Beginning left all numbers are weighted alternatively 1 and 2.
- 2.
- The total of the digits of all products is computed.
- 3.
- The sum of step 3 ist taken modulo 10.
- 4.
-
The check digit is the difference between 10 and the number from step
3 taken modulo 10.
HINT: The last digit of the 'Betriebsnummer' may be the check digit or the last digit of the sum of the constant 5 and the check digit.
METHODS
- is_valid($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.