sub baz { return 11 unless shift }

print 'baz(5): ', baz(5), "\n";
print 'baz(0): ', baz(0), "\n";
__END__
baz(5): 5
baz(0): 11

##</code><code>##

my @a = ( qw (onexxx txwxo txhrexe xfourx xxx five) );
my @b = map {
        $_ =~ s/x//g;
        $_ ? $_ : ();
        } @a;
print Dumper(\@b);
__END__
$VAR1 = [
          'one',
          'two',
          'three',
          'four',
          'five'
        ];

##</code><code>##

$VAR1 = [
          'one',
          'two',
          'three',
          'four',
          '',
          'five'
        ];