I agree that it's easier to use references throughout your program, rather than having to deal with real arrays and references to arrays. The same applies to hashes. One other thing is that you can use the arrow operator to index into the array refererence with square brackets, as the example below demonstrates. You can do a similar thing with hash references. 
#!/usr/bin/perl

use strict;
use warnings;

run();

sub run
{
    my $arr1 = [0 .. 12];
    my $arr2 = ['a' .. 'l'];

    print "before:\n";
    print "arr1 = @{$arr1}\n";
    print "arr2 = @{$arr2}\n";

    # because we're passing references to arrays, any changes
    # made to the arrays in the subroutine will affect the arrays
    # here as well. No need to return the arrays.
    f($arr1, $arr2);

    # use the arrow operator and square brackets to index the
    # array, same as in the subroutine below - same syntax,
    # less confusing
    $arr1->[7] = "SEVEN!";

    print "after:\n";
    print "arr1 = @{$arr1}\n";
    print "arr2 = @{$arr2}\n";
}

sub f
{
    my ($arr1, $arr2) = @_;

    for (my $i = 0; $i < 5; $i++)
    {
        # shuffle some stuff around
        my $index1 = rand($#$arr1);
        my $index2 = rand($#$arr2);

        # use the arrow operator and square brackets to index
        # the array through a reference
        my $tmp = $arr1->[$index1];
        $arr1->[$index1] = $arr2->[$index2];
        $arr2->[$index2] = $tmp;
    }
}

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In reply to Re^2: Help with references by beable
in thread Help with references by coldmiser

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