NAME

CheckDigits::MXX_005 - compute check digits for ESR9 (CH)

SYNOPSIS

  use Algorithm::CheckDigits;

  $esr = CheckDigits('esr9');

  if ($esr->is_valid('123456786')) {
        # do something
  }

  $cn = $esr->complete('12345678');
  # $cn = '123456786'

  $cd = $esr->checkdigit('123456786');
  # $cd = '6'

  $bn = $esr->basenumber('123456786');
  # $bn = '12345678'

DESCRIPTION

ALGORITHM

1.: Digits are processed left to right. For the first digit applies the balance is 0.
2.: The new balance is taken from the balance table according to the current balance (row) and the digit (column).
3.: The check digit is the difference from the last balance to 10 taken 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>"