my $result = 'hello';
$result or die "I'm dead";

$result = undef; 
$result or die "I'm dead down here.";

--output:--
I'm dead down here. at line 5.


##</code><code>##

my ($x, $y, $z);
$x = $y = $z = 20;
print "$x $y $z";

--output:--
20 20 20