CheckDigits::M11_002 − compute check digits for PZN (DE)
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'); # $bn = '487780'
ALGORITHM
1. |
From left to right beginning with the first position all digits are multiplied with 2,3,4,... |
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2. |
The sum of all products is computed. |
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3. |
The checkdigit ist the sum of step 2 taken modulo 11. |
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4. |
If the checkdigit is ’10’ the whole number is not taken as a PZN . |
METHODS
is_valid($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.
EXPORT
None by default.
Mathias Weidner, <mathias AT weidner DOT in−bad−schmiedeberg.de>
perl, CheckDigits, www.pruefziffernberechnung.de.