use strict;
use warnings;

local $\="\n";
my $hr;

print '$hr ',      defined $hr     ? 'defined' : 'undefined';

print '$hr->{a} ', exists $hr->{a} ? 'exists'  : 'doesn\'t exist';

print '$hr ',      defined $hr     ? 'defined' : 'undefined';

print '$hr is ',   $hr;

##</code><code>##

$hr undefined
$hr->{a} doesn't exist
$hr defined
$hr is HASH(0x3d51c0)