NAME¶
CheckDigits::M11_013 - compute check digits for VAT Registration Number (GR)
SYNOPSIS¶
use Algorithm::CheckDigits;
$ustid = CheckDigits('ustid_gr');
if ($ustid->is_valid('123456783')) {
# do something
}
$cn = $ustid->complete('12345678');
# $cn = '123456783'
$cd = $ustid->checkdigit('123456783');
# $cd = '3'
$bn = $ustid->basenumber('123456783');
# $bn = '12345678';
DESCRIPTION¶
ALGORITHM¶
- 1.
- Beginning right with the digit before the checkdigit all
digits are weighted with 2 ** position. I. e. the last digit is multiplied
with 2, the next with 4, then 8 and so on.
- 2.
- The weighted digits are added.
- 3.
- The sum from step 2 is taken modulo 11.
- 4.
- If the sum from step 3 is greater than 9, the check sum is
0 else it is the sum itself.
METHODS¶
- is_valid($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 the check digits of $number if $number has valid
check digits.
Return '' otherwise.
EXPORT¶
None by default.
AUTHOR¶
Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>
SEE ALSO¶
perl, CheckDigits,
www.pruefziffernberechnung.de,