Also, remember using reference allows you to modify the actual variable, where normally you will just modify a copy.

I'm sure you understand what really happens in a sub, but your wording is a bit vague, so I'll clarify this for monks who might not be familiar with this issue.

You will only modify a copy of a variable passed to a sub if you copy the arguments to new variables. If you modify the @_ array directly, you modify the original variables. Run the following snippet to see what I mean:

#!/usr/bin/perl -w
use strict;

my $test = "Hi there!";
change($test);
print $test;

sub change {
    $_[0] = "Hey, this is different!\n";
}
[download]

Cheers,
Ovid

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