CheckDigits::MBase_002(3) compute check digits for blood bags (DE), BZU.

## SYNOPSIS

use Algorithm::CheckDigits;
\$bb = CheckDigits('blutbeutel');
if (\$bb->is_valid('2761011234567893')) {
# do something
}
\$cn = \$bb->complete('276101123456789');
# \$cn = '2761011234567893'
\$cd = \$bb->checkdigit('2761011234567893');
# \$cd = '3'
\$bn = \$bb->basenumber('2761011234567893');
# \$bn = '276101123456789';

## ALGORITHM

1.
2.
Beginning left you do the following for all digits
1.
S = (P + digit) modulo 10
2.
If S is 0 then S = 10.
3.
P = (2 * S) modulo 11
3.
The check digit is (11 - P) 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.

None by default.

## AUTHOR

Mathias Weidner, <[email protected]>