References in perl are nothing but pointers but you can't use it like
you do it in C with subtraction, increment and so on.
Perl is a higher level language the references have to be used the perl way.
For instance references allow us to have a hash of arrays. A big array
can be coverted into one element easily with a reference
and you can use that as a value in a hash.
For that matter you can even use function pointers are hash values.
This is in fact a common perl idiom. Of course in perl you
don't call it a function pointer; instead you say subroutine reference.
Anyway now let us look at a hash.
%h = ( 1 => "first", 2 => "second );
$h{1} is "first" and $h{2} is "second".
Now
%h = ( 1 => [1,2,45,100], 2 => $a);
$a = [1,100,"girish"];
Of course the second line should come on top of first.
Now you can do like this:
$aref = $h{1};
@arr = @{$aref};
You can build an array of references like this also.
@a = (1,2,3,4, [10,30,4], [1,3,4]);
$a[#a][0], $a[#a][1], $a[#a][2] will give 1,3,4
You can also obtain a reference to a hash.
%hs = ( 123 => 35, 100 => 20);
$ref = \%hs;
%hash = %{$ref};
Now, $hash{123} will give 35.
$ perldoc perllol
-Girish
--
G3 Tech
Networking appliance company
web: http://g3tech.in ?mail: girish at g3tech.in
