#!/usr/bin/perl
use strict;
use warnings;

# Ivan Novick
# ref_test.pl

# use the ref function to determine if a variable contains a reference or someother type
sub testit
{
    my $arg = shift;
    my $description = shift;

    # ref will evaluate to false if $arg is not a reference
    if (ref($arg))
    {
        # ref will print out the type that the reference is to
        print ref($arg) . " --- $description\n";
    } 
    else
    {
        print "NULL --- $description\n";
    }
}

my $myscalar = "aa";
my @myarray = qw/one two three/;
my %myhash = qw/key1 value1 key2 value2/;

my $ref1 = \$myscalar;
my $ref2 = \@myarray;
my $ref3 = \%myhash;

# ref returns NULL
testit("HELLO",     "literal");

# ref returns NULL
testit($myscalar,   "scalar");

# ref returns NULL
testit(@myarray,    "array");

# ref returns NULL
testit(%myhash,     "hash");

# ref returns SCALAR
testit($ref1,       "reference to a scalar");

# ref returns ARRAY
testit($ref2,       "reference to an array ");

# ref returns HASH
testit($ref3,       "reference to a hash");