Man pages sections > man3 > Algorithm::CheckDigits::M43_001

# CheckDigits::M43_001 - compute check digits for Code-39

 CheckDigits::M43_001(3pm) User Contributed Perl Documentation CheckDigits::M43_001(3pm)

## NAME

CheckDigits::M43_001 - compute check digits for Code-39

## SYNOPSIS

```  use Algorithm::CheckDigits;
\$c39 = CheckDigits('code_39');
if (\$c39->is_valid('AB-123K')) {
# do something
}
\$cn = \$c39->complete('AB-123');
# \$cn = 'AB-123K'
\$cd = \$c39->checkdigit('AB-123K');
# \$cd = 'K'
\$bn = \$c39->basenumber('AB-123K');
# \$bn = 'AB-123'
```

## DESCRIPTION

### ALGORITHM

1.
After replacing all non numeric letters with their respective values, the sum of all numbers is computers
2.
The checkdigit is the sum from step 1 taken modulo 43.

### 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.