NAME

CheckDigits::M11_009 - compute check digits NRIC (SG)

SYNOPSIS

  use Algorithm::CheckDigits;
  $nric = CheckDigits('nric_sg');
  if ($nric->is_valid('S1234567D')) {
        # do something
  }
  $cn = $nric->complete('S1234567');
  # $cn = 'S1234567D'
  $cd = $nric->checkdigit('S1234567D');
  # $cd = 'D'
  $bn = $nric->basenumber('S1234567D');
  # $bn = 'S1234567';

DESCRIPTION

ALGORITHM

1.

Beginning left every digit is weighted with 2, 7, 6, 5, 4, 3, 2

2.

The weighted digits are added.

3.

The sum from step 2 is taken modulo 11.

4.

The checkdigit is 11 minus the sum from step 3 converted to a character according to the following table:

  @cd = ('','A','B','C','D','E','F','G','H','I','Z','J', );

METHODS

is_valid($number): Returns true only if $number consists solely of numbers and hyphens and the two digits in the middle are valid check digits according to the algorithm given above.
Returns false otherwise,
complete($number): The check digit for $number is computed and inserted into the middle of $number.
Returns the complete number with check digit or '' if $number does not consist solely of digits, hyphens and spaces.
basenumber($number): Returns the basenumber of $number if $number has a valid check digit.
Return '' otherwise.
checkdigit($number): Returns '' if $number is valid.
Return undef otherwise.

EXPORT

None by default.

AUTHOR

Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>