my @array = ( 1, 2, 3 );

for my $elem ( @array ){
    say $elem;
}

##</code><code>##

my $aref = \@array;

##</code><code>##

ARRAY(0x9bfa8c8)

##</code><code>##

for my $elem ( @{ $aref } ){
    say $elem;
}

##</code><code>##

my $x  = $array[0];

##</code><code>##

my $y = $aref->[1];

##</code><code>##

$array[1]  = "assigning to array element 2";

##</code><code>##

$aref->[1] = "assigning to array element 2";

##</code><code>##

my %hash = ( a => 1, b => 2, c => 3 );

while ( my ( $key, $value ) = each %hash ){

    say "key: $key, value: $value";
}

##</code><code>##

my $href = \%hash;

##</code><code>##

while ( my ( $key, $value ) = each %{ $href } ){

    say "key: $key, value: $value";
}

##</code><code>##

my $x = $hash{ a };

##</code><code>##

my $y = $href->{ a };

##</code><code>##

$hash{ a }  = "assigning to hash key a";

##</code><code>##

$href->{ a } = "assigning to hash key a";

##</code><code>##

my @array = ( 1, 2, 3 );
my $aref = \@array;

# assign a new value to $b[0] through the reference

$aref->[0] = 99;

# print the array

for my $elem ( @array ){
    say $elem;
}

##</code><code>##

99
2
3

##</code><code>##

$array[0] = 99;
$aref->[0] = 99;

##</code><code>##

my @array = ( 1, 2, 3 );
my %hash  = ( a => 1, b => 2, c => 3 );

# take a reference to the array
my $aref = \@array;

# take a reference to the hash
my $href = \%hash;

# access the entire array through its reference
my $elem_count = scalar @{ $aref };

# access the entire hash through its reference
my $keys_count = keys %{ $href };

# get a single element through the array reference
my $element = $aref->[0];

# get a single value through the hash reference
my $value = $href->{ a };

# assign to a single array element through its reference
$aref->[0] = 1;

# assign a value to a single hash key through its ref
$href->{ a } = 1;