use warnings;
use strict;
use Data::Dumper;
no autovivification;

my %h = (a => 'alfa', b => 'beta'); 

print map { ">>$_<<\n" } $h{a}, $h{333}, $h{b};
print Dumper(\%h);

__END__

Use of uninitialized value $_ in concatenation (.) or string at 11112786.pl line 8.
>>alfa<<
>><<
>>beta<<
$VAR1 = {
          '333' => undef,
          'a' => 'alfa',
          'b' => 'beta'
        };