my $yanks = $baseball{yankees} || "";
my $mets  = $baseball{mets}    || "";
if ( $baseball{yankees} = $yanks.$mets )  {
    foreach $_ (keys %baseball) {
        print "$_ => $baseball{$_}\n";
    }
}

##</code><code>##

if ( $baseball{yankees}=($baseball{yankees} || ""). ($baseball{mets} || "") )  {
    foreach $_ (keys %baseball) {
        print "$_ => $baseball{$_}\n";
    }
}