my %hash = { a=>1, b=>2 };
my $ref = \%hash;

# This will give you a nice dump of your hash
print Dumper($ref);

# This will give you the same kind of dump
print Dumper(\%hash);

# This will give you a *HORRIBLE* dump:
print Dumper(%hash);
# It'll give you something like:
$VAR1 = 'a';
$VAR2 = 1;
$VAR3 = 'b';
$VAR4 = 2;