search.cpan.org is shutting down
Mathias Weidner > Algorithm-CheckDigits > Algorithm::CheckDigits::M23_002

Algorithm-CheckDigits-v1.3.2.tar.gz

Dependencies

Annotate this POD

# CPAN RT

 Open 0
View/Report Bugs
Module Version: v1.3.2

# NAME

CheckDigits::M23_002 - compute check digits for VAT Registration Number (IE)

# SYNOPSIS

```  use Algorithm::CheckDigits;

\$dni = CheckDigits('ustid_ie');

if (\$dni->is_valid('8473625E')) {
# do something
}

\$cn = \$dni->complete('8473625');
# \$cn = '8473625E'

\$cd = \$dni->checkdigit('8473625E');
# \$cd = 'E'

\$bn = \$dni->basenumber('8473625E');
# \$bn = '8473625'```

# DESCRIPTION

## ALGORITHM

1. Beginning right all digits are weighted with their position in the number (i.e. the number left from the check digit is multiplied with 2, the next with 3 and so on).
3. The check digit is the sum from step 2 modulo 23. This number is expressed as the corresponding letter from the alphabet where A-V correspond to 1-22 and W stands for check digit 0.

## 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.

None by default.

# AUTHOR

Mathias Weidner, `<mamawe@cpan.org>`