Ruby vs. Perl
By brian d foy, December 01, 2002
Ruby vs. Perl
Dec02: Ruby vs. Perl
1 sub as_ean
2 {
3 my $self = shift;
4
5 my $isbn = ref $self ? $self->as_string([]) :_common_format $self;
6
7 return unless ( defined $isbn and length $isbn == 10 );
8
9 my $ean = '978' . substr($isbn, 0, 9);
10
11 my $sum = 0;
12 foreach my $index ( 0, 2, 4, 6, 8, 10 )
13 {
14 $sum += substr($ean, $index, 1);
15 $sum += 3 * substr($ean, $index + 1, 1);
16 }
17
18 $ean .= ( 10 * ( int( $sum / 10 ) + 1 ) - $sum ) % 10;
19
20 return $ean;
21 }
Example 1: The as_ean subroutine.
