picard:~ [13:53:28]$ cat inc.pl
#!/usr/bin/perl -l

use strict;
use warnings;

sub inc { $_++ for @_ }

my @array;
$array[1]=666;
inc @array;
print "@array";

__END__
picard:~ [13:53:31]$ ./inc.pl
Use of uninitialized value in join or string at ./inc.pl line 11.
     667