my %types = (
  hash => {},
  array => [],
  string => "abc",
  int   => 123
  sub => \&my_sub
  ...
);

if($types{array} =~ /^ARRAY/) { print "ein array"; }
if($types{hash} =~ /^HASH/) { print "ein hash"; }

my $var_a = 'string';
my $var_b = {key => 2};
my $var_c = [1,2];

print ref($var_a),"\n",ref($var_b),"\n",ref($var_c);