@check = ( 3, 4, 7, 2 );
@other = ( 2, 4, 5, 7, 3);
It's easy, though time consuming (as in consuming CPU cycles) using the "foreach" command:
my @not_there; # where we can mark values *not* duped
foreach my $c (@check) {
my $there;
foreach my $o (@other) {
if ($o eq $c) { $there++; }
}
if (! $there) { push @not_there, $c; }
}
..then, in theory (I haven't run the above code) you should have a list of all the values NOT duplicated in @not_there.