$count = 10;

##</code><code>##

$copy = $count;

##</code><code>##

$ref = \$count; # initialise $ref's value to be a reference to $count

##</code><code>##

print "ref $ref\n";

ref SCALAR(0x000003e8)

##</code><code>##

print "ref value $$ref\n";

ref value 10

##</code><code>##

@array = (10, 20, 30);

##</code><code>##

@copy = @array;

##</code><code>##

$ref = \@array;

##</code><code>##

print "ref $ref\n";

ref ARRAY(0x000003e8)

##</code><code>##

print $ref->[1];

20

##</code><code>##

print $$ref[1];

20

##</code><code>##

%hash = (a => 1, b => 2);

##</code><code>##

$ref = \%hash;

##</code><code>##

print "ref $ref";

HASH(000003e8)

print $ref->{b};

2

print $$ref{b};

2

##</code><code>##

$array[1] = @another; # nope - number of entries in @another is assigned to $array[1]

##</code><code>##

$array[1] = \@another;

print $array[1]->[0]; # the first entry in the referenced array

##</code><code>##


sub func {
   my (@arr) = @_;

   if (@arr[1] eq 'command') {
   ...
}

func(@ten_million);

##</code><code>##

sub func {
   my ($aref) =@_;

   if ($aref->[1] eq 'command') {
   ...
}

func(\@ten_million);

##</code><code>##

$ref = \@array;

print "ref $ref\n";

ARRAY(000003e8)

$ref++;

print "ref $ref\n";

1001