because ($self) = @_; makes a copy of the reference not a copy of the thing(s) the reference points at.

consider this 


sub pass_var {
        my ($foo,$bar) = @_;

        print "foo: $foo bar: $bar\n";
        $foo = 'c1';
        $bar = 'c2';

        print "changed: foo: $foo bar: $bar\n";
}
        

sub pass_ref {
        my ($hash) = @_;

        print "hash: $hash->{'key'}\n";

        $hash->{'key'} = 'c1';

        print "changed: hash: $hash->{'key'}\n";
        print "hashref is: $hash\n";
}

my $hash;
my $foo;
my $bar;


$foo = 1;
$bar = 2;

$hash = {'key' => 1 };

&pass_var($foo,$bar);
print "after: foo: $foo bar: $bar\n";

&pass_ref($hash);
print "after: hash: $hash->{'key'}\n";

print "hashref is: $hash\n";

[download]
which yields this output 
foo: 1 bar: 2
changed: foo: c1 bar: c2
after: foo: 1 bar: 2
hash: 1
changed: hash: c1
hashref is: HASH(0x80f86e0)
after: hash: c1
hashref is: HASH(0x80f86e0)

[download]
See how the hash both in and out of the sub point to the same memory address?

/\/\averick

In reply to Re: How does my $self = (@_) actually work? by maverick
in thread How does my $self = (@_) actually work? by princepawn

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.