$hash{key};         # single dimension hash
$hash{key1}{key2};  # multiple dimension hash

##</code><code>##

Subroutine calls and lookups of individual array elements arise often enough that it gets 
cumbersome to use method 2. As a form of syntactic sugar, the examples for method 2 may 
be written: 

    $arrayref->[0] = "January";   # Array element
    $hashref->{"KEY"} = "VALUE";  # Hash element
    $coderef->(1,2,3);            # Subroutine call

The left side of the arrow can be any expression returning a
reference, including a previous dereference. 
##</code><code>##

 
    $array[$x]->{"foo"}->[0] = "January";
This is one of the cases we mentioned earlier in which references could spring into 
existence when in an lvalue context. Before this statement, $array[$x]may have been 
undefined. If so, it's automatically defined with a hash reference so that we can 
look up {"foo"}in it. Likewise $array[$x]->{"foo"}will automatically get defined 
with an array reference so that we can look up [0]in it. 
One more thing here.  
##</code><code>##

 

    $array[$x]{"foo"}[0] = "January";
Which, in the degenerate case of using only ordinary arrays, gives you multidimensional 
arrays just like C's: 

    $score[$x][$y][$z] += 42;
Well, okay, not entirely like C's arrays, actually.
C doesn't know how to grow its arrays on demand. 
Perl does. 

##</code><code>##

$$player_dbref{player_name}{ip}{user_id};