NAME

       CheckDigits::M10_005 - compute check digits for Deutsche Post Identcode/Leitcode (DE)

SYNOPSIS

         use Algorithm::CheckDigits;

         $ic = CheckDigits('identcode_dp');

         if ($ic->is_valid('21.802 580.906 6')) {
               # do something
         }

         $cn = $ic->complete('21.802 580.906');
         # $cn = '21.802 580.9066'

         $cd = $ic->checkdigit('21.802 580.906 6');
         # $cd = '6'

         $bn = $ic->basenumber('21.802 580.906 6');
         # $bn = '21.802 580.906'

DESCRIPTION

   ALGORITHM
       1.  Beginning left all numbers are weighted alternatively 4 and 9.

       2.  The sum of all products is computed.

       3.  The sum of step 3 ist taken modulo 10.

       4.  The check digit is the difference between 10 and the number from step 3.

   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>

SEE ALSO

       perl, CheckDigits, www.pruefziffernberechnung.de.