SYNOPSIS
use Algorithm::CheckDigits;
$verhoeff = CheckDigits('verhoeff');
if ($verhoeff->is_valid('14567894')) {
# do something
}
$cn = $verhoeff->complete('1456789');
# $cn = '14567894'
$cd = $verhoeff->checkdigit('14567894');
# $cd = '4'
$bn = $verhoeff->basenumber('14567894');
# $bn = '1456789'
DESCRIPTION
ALGORITHM
- 1.
- Right to left all digits are permutated according to a permutation table.
- 2.
- The permutated digits are combined using a die.der table. The first with the second, the result with the third, this result with the fourth and so on.
- 3.
- The result of the last combination in the die.der table is in such a way combined that the result is 0 (zero). The number used for this combination is the checksum.
For details look at the source.
METHODS
- is_valid($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 $number does not consist solely of digits.
- basenumber($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.