use Data::Dumper;

my %words = ( 'hello' => 'world' );

print 'type a word: ';
chomp( my $inData = <> );
print $words{$inData} //= "Key '$inData' doesn't exist.\n";

print Dumper \%words;
##</code><code>##

type a word: Bonjour
Key 'Bonjour' doesn't exist.
$VAR1 = {
          'hello' => 'world',
          'Bonjour' => 'Key \'Bonjour\' doesn\'t exist.
'
        };