#! perl
use strict;
use warnings;

print "\nWITH autovivification:\n";
my $hashref1;
printf "1. \$hashref1 %s defined\n", (defined $hashref1 ? 'IS' : 'is NOT');
my $foo = $hashref1->{bar};
printf "2. \$hashref1 %s defined\n", (defined $hashref1 ? 'IS' : 'is NOT');

no autovivification;

print "\nWITHOUT autovivification:\n";
my $hashref2;
printf "3. \$hashref2 %s defined\n", (defined $hashref2 ? 'IS' : 'is NOT');
my $baz = $hashref2->{bar};
printf "4. \$hashref2 %s defined\n", (defined $hashref2 ? 'IS' : 'is NOT');