SYNOPSIS
use Algorithm::CheckDigits;
$nric = CheckDigits('nric_sg');
if ($nric->is_valid('S1234567D')) {
# do something
}
$cn = $nric->complete('S1234567');
# $cn = 'S1234567D'
$cd = $nric->checkdigit('S1234567D');
# $cd = 'D'
$bn = $nric->basenumber('S1234567D');
# $bn = 'S1234567';
DESCRIPTION
ALGORITHM
- 1.
- Beginning left every digit is weighted with 2, 7, 6, 5, 4, 3, 2
- 2.
- The weighted digits are added.
- 3.
- The sum from step 2 is taken modulo 11.
- 4.
-
The checkdigit is 11 minus the sum from step 3 converted to a
character according to the following table:
@cd = ('','A','B','C','D','E','F','G','H','I','Z','J', );
METHODS
- is_valid($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.