Algorithm::CheckDigits::MXX_005(3pm)

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, "<[email protected]>"