Difference between revisions of "Perl/Basics/Variables and Data Types/References"

Latest revision as of 01:58, 19 July 2012

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);