I would pass the array by reference. As an added bonus, you don't have to return it, as the subroutine will update the original array directly. (This is not always a good thing but probably is desired here.)

Example: 

my @array = ();
     # ... populate array here
&multi(\@array);
     # ... later, the subroutine:
sub multi
{
     my $arrayReference = shift;
     my @localArray = @$arrayReference;
          # ... do stuff to @localArray
          # ... it actually affects the original array
}

[download]

A more full demonstration is hidden behind the readmoretag: 

#!/usr/bin/perl

use strict;

{
    my @originalArray = ();

    print "-----[ initArrayLocally() ]---------------\n";
    my $initializedArrayReference = &initArrayLocally(\@originalArray)
+;
    my @array = @$initializedArrayReference;
    print "Value of \@array[5][5][5] = '$array[5][5][5]'\n";

    print "-----[ modifyArrayLocally() ]---------------\n";
    my $newArrayReference = &modifyArrayLocally(\@array);
    my @newArray = @$newArrayReference;
    print "Value \@array[5][5][5] = '$array[5][5][5]'\n";
    print "Value \@newarray[5][5][5] = '$newArray[5][5][5]'\n";

    print "-----[ modifyArrayByReference() ]---------------\n";
    &modifyArrayByReference(\@array);
    print "Value \@array[5][5][5] = '$array[5][5][5]'\n";

    print "-----[ Done ]---------------\n";
}

sub initArrayLocally
{
    my $arrayReference = shift;
    my @localArray = @$arrayReference;
    my $value = 0;
    # OMG This looks like FORTRAN or BASIC from 35 years ago!
    for (my $i=0; $i<10; $i++)
    {
        for (my $j=0; $j<10; $j++)
        {
            for (my $k=0; $k<10; $k++)
            {
                $localArray[$i][$j][$k] = ++$value;
            }
        }
    }
    return \@localArray;
}

sub modifyArrayLocally
{
    my $arrayReference = shift;
    my @localArray = @$arrayReference;
    $localArray[5][5][5] = 42;

    return \@localArray;
}

sub modifyArrayByReference
{
    my $arrayReference = shift;
    ${$arrayReference}[5][5][5] = 99;

    return;
}


exit;

__END__


C:\Steve\Dev\PerlMonks\P-2013-10-18@2257-SubRet-3DArray>perl ret3d2.pl
-----[ initArrayLocally() ]---------------
Value of @array[5][5][5] = '556'
-----[ modifyArrayLocally() ]---------------
Value @array[5][5][5] = '42'
Value @newarray[5][5][5] = '42'
-----[ modifyArrayByReference() ]---------------
Value @array[5][5][5] = '99'
-----[ Done ]---------------

[download]

In reply to Re: Returning Multidimensional array from subroutine to main code ; by marinersk
in thread Returning Multidimensional array from subroutine to main code ; by vels

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