ch09.062_prob

Perl Best Practices the source code

##############################################################################
## Code fragment (NOT RECOMMENDED) from Chapter 9 of "Perl Best Practices"  ##
##     Copyright (c) O'Reilly & Associates, 2005. All Rights Reserved.      ##
##  See: http://www.oreilly.com/pub/a/oreilly/ask_tim/2001/codepolicy.html  ##
##############################################################################


# Standard modules...
use strict;
use warnings;
use IO::Prompt;
use Carp;
use English qw( -no_match_vars );
use Data::Alias;
use Readonly;

my @sheep = (2,4,6,8,10);
my @goats = (1,3,5,7,9);

sub swap_arrays (\@\@) {
    my ($array1_ref, $array2_ref) = @_;
 
    my @temp_array = @{$array1_ref};
    @{$array1_ref} = @{$array2_ref};
    @{$array2_ref} = @temp_array;
 
    return;
}
 
# and later...
 
swap_arrays(@sheep, @goats);      # Implicitly pass references

use Data::Dumper 'Dumper';
warn Dumper [ 'SHEEP', @sheep ];
warn Dumper [ 'GOATS', @goats ];