NAME¶
CheckDigits::MXX_003 - compute check digits for DEM
SYNOPSIS¶
use Algorithm::CheckDigits;
$dem = CheckDigits('dem');
if ($dem->is_valid('GD0645027K1')) {
# do something
}
$cn = $dem->complete('GD0645027K');
# $cn = 'GD0645027K1'
$cd = $dem->checkdigit('GD0645027K1');
# $cd = '1'
$bn = $dem->basenumber('GD0645027K1');
# $bn = 'GD0645027K'
DESCRIPTION¶
ALGORITHM¶
The algorithm is a variation of the Verhoeff scheme.
- 0
- All letters are changed to numbers.
- 1
- All digits are permutated according to a permutation
table.
- 2
- The permutated digits are combined using a dieeder table.
The first with the second, the result with the third, this result with the
fourth and so on.
- 3
- The result of the last combination in the dieeder table is
in such a way combined that the result is 0 (zero). The number used for
this combination is the checksum.
For details look at the source.
METHODS¶
- is_valid($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 $number does not
consist solely of digits and spaces.
- basenumber($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.
EXPORT¶
None by default.
AUTHOR¶
Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>
THANKS¶
SEE ALSO¶
perl, CheckDigits,
www.pruefziffernberechnung.de,