#!/usr/local/bin/perl
# Jaime Prilusky, 2004

Some examples of references:

  $scalarref = \$foo;
  $arrayref  = \@ARGV;
  $hashref   = \%ENV;
  $coderef   = \&handler;
  $globref   = \*foo;

Reference to an anonymous array

  $arrayref = [1, 2, ['a', 'b', 'c']];
  $arrayref->[2][1] would have the value "b"

Reference to an anonymous hash

  $hashref = {
    'Adam'  => 'Eve',
    'Clyde' => 'Bonnie',
  };
  $hashref->{'Clyde'} would have the value 'Bonnie'
  
Reference to an anonymous subroutine

  $coderef = sub { 
     my($msg) = @_; 
     print "Message is: $msg\n" 
  };
  $coderef->("Hi");