I have used the method of passing arrays by reference to a subroutine so I can prevent them from being turned into one long array w/out problems...many times.
Now, however, I've come across the need to change the elements' values inside the subroutine, and I expected (because they are array refs) the values of those elements to be changed outside of the subroutine too. That is not happening though. Could somebody please point out my mistake.
Here is a sample script that illustrates my problem.
#!/usr/local/bin/perl
### Temp script to replicate oid_mod.pl ###
use strict;
my @a1 = qw(a b c);
my @a2 = qw(d e f);

foreach (@a2) {
    print "$_\n";
}
changem(\@a1,\@a2); #pass-by-ref to allow extraction
foreach (@a2) {
    print "$_\n";
}

sub changem {
    my ($r1,$r2) = @_; 
    my @arr1 = @{$r1};
    my @arr2 = @{$r2};
    print "BEFORE: $arr2[1]\n";
    $arr2[1] = "q";
    print "AFTER: $arr2[1]\n";
}

[download]
Expected Output: 
d
e
f
BEFORE: e
AFTER: q
d
q
f

[download]
Actual Output: 
d
e
f
BEFORE: e
AFTER: q
d
e
f

[download]
Why, when I print @a2 after the subroutine, has the value of $a2[1] not changed?
Thank you in advance.

In reply to Array references inside a subroutine by Anonymous Monk

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