use Data::Dumper;
my %hash = ( key_1 => 'value_1', key_2 => 'value_2' );
print Dumper(%hash);

__END__
$VAR1 = 'key_2';
$VAR2 = 'value_2';
$VAR3 = 'key_1';
$VAR4 = 'value_1';