Clone(3) User Contributed Perl Documentation Clone(3)

Clone - recursively copy Perl datatypes

use Clone 'clone';
my $data = {
   set => [ 1 .. 50 ],
   foo => {
       answer => 42,
       object => SomeObject->new,
   },
};
my $cloned_data = clone($data);
$cloned_data->{foo}{answer} = 1;
print $cloned_data->{foo}{answer};  # '1'
print $data->{foo}{answer};         # '42'

You can also add it to your class:

package Foo;
use parent 'Clone';
sub new { bless {}, shift }
package main;
my $obj = Foo->new;
my $copy = $obj->clone;

This module provides a clone() method which makes recursive copies of nested hash, array, scalar and reference types, including tied variables and objects.

clone() takes a scalar argument and duplicates it. To duplicate lists, arrays or hashes, pass them in by reference, e.g.

my $copy = clone (\@array);
# or
my %copy = %{ clone (\%hash) };

Storable's dclone() is a flexible solution for cloning variables, albeit slower for average-sized data structures. Simple and naive benchmarks show that Clone is faster for data structures with 3 or fewer levels, while dclone() can be faster for structures 4 or more levels deep.

Copyright 2001-2022 Ray Finch. All Rights Reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Ray Finch "<rdf@cpan.org>"

Breno G. de Oliveira "<garu@cpan.org>", Nicolas Rochelemagne "<atoomic@cpan.org>" and Florian Ragwitz "<rafl@debian.org>" perform routine maintenance releases since 2012.

2024-09-02 perl v5.40.0