use strict;
"blah" =~ /(a)/;       # now we've set $1 at the global scope

my $i = "mmmm9";
my $a = match_rtn( $i );
print $a, "\n";

$i = "mmm";
$a = match_rtn( $i );
print $a, "\n";        # ook! this isn't undefined!

sub match_rtn {
    my $str = shift;
    $str =~ m/(\d+)/;
    return $1;   
}

##</code><code>##

{
    $_ = 'blah';
    /(a)/;
    print "$1\n"; # prints: a
}

print "$1\n"; # unitialized warning

##</code><code>##


$_ = 'blah';
/(\w)/;
print "$1\n"; # prints: b
/(\d)/;
print "$1\n"; # still prints: b

{
    /(a)/;
    print "$1\n"; # prints: a
}

print "$1\n"; # prints: b