Perl/Basics/Variables and Data Types/References

A reference is very similar to a pointer in C.

Hash References

A hash reference is a scalar created using the \ operator as follows:

my %user; $user{'name'} = "hatter"; $user{'network'} = "irc.blackhatacademy.org";   my $hashref = \%user;

Once you've created a hashref (hash reference) you must use pointers to access a key:

print $user->{'name'} . "\n"; print $user->{'network'} . "\n";

Callback References

This involves user-defined functions. User-defined functions are covered later in this article. A callback reference is a scalar that points to a function. To create a callback reference:

my $callback = \&function_name;

To execute the callback function and pass it arguments:

$callback->($arg1, $arg2);