Getting values in Hash Reference?

[gube]

Hi monks,

I have a doubt in getting values in hash reference. Please see my by below code and comment and give me pour some idea about the code. I cannot understand this code, how it's working please some one give me an idea

"print @$hash_ref{'a', 'b'};"

#!/usr/bin/perl -w
use strict;
use warnings;
use Data::Dumper;
#Hash
my %hash = ('a' => 1,  'b' => 2);
#To print the two values i have mentioned keys
print @hash{'a', 'b'};
#Hash Reference
my $hash_ref = \%hash;
#To print the two values i have mentioned keys i am getting error (Glo
+bal symbol "@hash_ref" requires explicit package name)
print @hash_ref->{'a', 'b'};
#Prints values without error
print @$hash_ref{'a', 'b'};