# algorithm::checkdigits::m11_015(3pm) [debian man page]

```CheckDigits::M11_015(3pm)				User Contributed Perl Documentation				 CheckDigits::M11_015(3pm)

NAME
CheckDigits::M11_015 - compute check digits for ESR5 (CH)

SYNOPSIS
use Algorithm::CheckDigits;

\$ustid = CheckDigits('esr5_ch');

if (\$ustid->is_valid('123456786')) {
# do something
}

\$cn = \$ustid->complete('12345678');
# \$cn = '123456786'

\$cd = \$ustid->checkdigit('123456786');
# \$cd = '6'

\$bn = \$ustid->basenumber('123456786');
# \$bn = '12345678';

DESCRIPTION
ALGORITHM
1.  Beginning left every digit is weighted with 7,9,10,5,8,4,2.

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. Is the difference 10, the number won't be taken. If the difference is 11, the
checkdigit is 0.

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 the check digits of \$number if \$number has valid check digits.

Return '' otherwise.

EXPORT
None by default.

AUTHOR

perl, CheckDigits, www.pruefziffernberechnung.de,

perl v5.10.0							    2008-05-17						 CheckDigits::M11_015(3pm)```

## Check Out this Related Man Page

```CheckDigits::M11_011(3pm)				User Contributed Perl Documentation				 CheckDigits::M11_011(3pm)

NAME
CheckDigits::M11_011 - compute check digits for VAT Registration Number (NL)

SYNOPSIS
use Algorithm::CheckDigits;

\$ustid = CheckDigits('ustid_nl');

if (\$ustid->is_valid('123456782')) {
# do something
}
if (\$ustid->is_valid('123456782B04')) {
# do something
}

\$cn = \$ustid->complete('12345678');
# \$cn = '123456782'
\$cn = \$ustid->complete('12345678.B04');
# \$cn = '123456782B04'

\$cd = \$ustid->checkdigit('123456782');
# \$cd = '2'
\$cd = \$ustid->checkdigit('123456782B04');
# \$cd = '2'

\$bn = \$ustid->basenumber('123456782');
# \$bn = '12345678';
\$bn = \$ustid->basenumber('123456782B04');
# \$bn = '12345678.B04';

DESCRIPTION
This VATRN has 12 "digits", the third last must be a B, the fourth last is the checkdigit. I don't know anything about the meaning of the
last two digits.

You may use the whole VATRN or only the first eight digits to compute the checkdigit with this module.

ALGORITHM
1.  Beginning right with the digit before the checkdigit all digits are weighted with their position. I.e. the digit before the checkdigit
is multiplied with 2, the next with 3 and so on.

2.  The weighted digits are added.

3.  The sum from step 2 is taken modulo 11.

4.  If the sum from step 3 is 10, the number is discarded.

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 the check digits of \$number if \$number has valid check digits.

Return '' otherwise.

EXPORT
None by default.

perl, CheckDigits, www.pruefziffernberechnung.de,

AUTHOR