SYNOPSIS
use Algorithm::CheckDigits;
$pzn = CheckDigits('pzn');
if ($pzn->is_valid('4877800')) {
# do something
}
$cn = $pzn->complete('487780');
# $cn = '4877800'
$cd = $pzn->checkdigit('4877800');
# $cd = '0'
$bn = $pzn->basenumber('4877800');
# $bn = '487780'
DESCRIPTION
ALGORITHM
- 1.
- From left to right beginning with the first position all digits are multiplied with 2,3,4,...
- 2.
- The sum of all products is computed.
- 3.
- The checkdigit ist the sum of step 2 taken modulo 11.
- 4.
- If the checkdigit is '10' the whole number is not taken as a PZN.
METHODS
- is_valid($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.