NAME

CheckDigits::M09_001 - compute check digits for Euro notes

SYNOPSIS

  use Algorithm::CheckDigits;

  $euro = CheckDigits('euronote');

  if ($euro->is_valid('X07738250357')) {
	# do something
  }

  $cn = $euro->complete('X0773825035');     # $cn = 'X07738250357'

  $cd = $euro->checkdigit('X07738250357'); # $cd = '7'

  $bn = $euro->basenumber('X07738250357'); # $bn = 'X0773825035'
  

DESCRIPTION

ALGORITHM

1. Letters are replaced with their position in the alphabet ('A' = 1, ...).

2. The total of the digits of all numbers is computed.

3. This sum is taken modulo 9.

4. The check digit is the difference between 8 and the number of step 3.

To validate the last digit of the total of the digits of all numbers inclusive check digit must be 8.

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.

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.