| Algorithm::CheckDigits::MXX_002(3) | User Contributed Perl Documentation | Algorithm::CheckDigits::MXX_002(3) | 
NAME¶
CheckDigits::MXX_002 - compute check digits for CAS
SYNOPSIS¶
  use Algorithm::CheckDigits;
  $cas = CheckDigits('cas');
  if ($cas->is_valid('1333-74-0')) {
        # do something
  }
  $cn = $cas->complete('1333-74-');
  # $cn = '1333-74-0'
  $cd = $cas->checkdigit('1333-74-0');
  # $cd = '0'
  $bn = $cas->basenumber('1333-74-0');
  # $bn = '1333-74-'
DESCRIPTION¶
ALGORITHM¶
- 1.
 - Beginning right with the second digit all digits are weighted ascending starting with 1.
 - 2.
 - The sum of those products is computed.
 - 3.
 - The checksum is the last digit of the sum from step 2 (modulo 10).
 
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, "<mamawe@cpan.org>"
THANKS¶
Aaron W. West pointed me to a fault in the computing of the check digit.
HERMIER Christophe made me aware that CAS is now assigning 10-digit CAS Registry Numbers (http://www.cas.org/newsevents/10digitrn.html)
SEE ALSO¶
perl, CheckDigits, www.pruefziffernberechnung.de, www.cas.org http://www.cas.org/expertise/cascontent/registry/checkdig.html
| 2021-11-17 | perl v5.26.1 |