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 2001−2019 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 "<>"

Breno G. de Oliveira "<>" and Florian Ragwitz "<>" perform routine maintenance releases since 2012.