#!/usr/bin/perl

use strict;
use warnings;

my %bar = ();

$bar{not_existing} = 1;
$bar{"is_existing"} = 1;

my $bar1 = $bar{not_existing};
my $bar2 = $bar{"is_existing"};
my $bar3 = $bar{really_not_existing};

my $key4 = "value_not_existing";
my $bar4 = $bar{$key4};

my $key5;
my $bar5 = $bar{$key5};

exit;

__END__

C:\Steve\devcvs\mapgen>\steve\t\t2.pl
Use of uninitialized value $key5 in hash element at C:\steve\t\t2.pl line 19.