G'day Leudwinus,

"I am still trying to wrap my head around ..."

You're using terms — pointer, address, memory location — which I suspect you've picked up from one or more other languages. You are then attempting to apply those terms to Perl, assuming they have the same meaning. I think this may be the source of your problems.

I'd suggest the first thing to do would be to look at perlintro; in particular, the "Perl variable types" section. At the end of that section you'll find the gentlest of introductions to references with a list of other links to more information; I'd suggest checking out perlreftut first.

Consider the following:

$ perl -E '
    my $x = 5;
    say $x;
    my $y = \$x;
    say $y;
    say $$y;
    $$y += 3;
    say $x;
'
5
SCALAR(0x60008a1c8)
5
8
[download]

• $x has the value 5.
• $y is assigned a reference to $x.
• $y has the value SCALAR(0x60008a1c8).
• Dereferencing $y (with $$y) gives you back $x.
• Incrementing $$y by 3 is the same as incrementing $x by 3.
• $x now has the value 8.

You can reference and dereference to great depths if you want; as in this exaggerated example:

$ perl -E 'my $x = 5; say $x; my $y = \\\\$x; $$$$$y += 3; say $x'
5
8
[download]

The construct \(...), where ... is some list, evaluates to a list of references to each element of the list:

$ perl -E 'say for \(qw{1 2 3})'
SCALAR(0x60008a730)
SCALAR(0x60008a7d8)
SCALAR(0x60008a748)
[download]

You can take references to other data types:

$ perl -E 'my @x = qw{1 2 3}; say for @x; my $y = \@x; say $y'
1
2
3
ARRAY(0x60008a8e8)
[download]

and dereference them:

$ perl -E 'my @x = qw{1 2 3}; say for @x; my $y = \@x; say $y; say for
+ @$y'
1
2
3
ARRAY(0x60008a828)
1
2
3
[download]

You can take references to references:

$ perl -E 'my @x = qw{1 2 3}; say for @x; my $y = \\@x; say $y'
1
2
3
REF(0x600003e80)
[download]

and dereference them one level at a time:

$ perl -E 'my @x = qw{1 2 3}; say for @x; my $y = \\@x; say $y; say $$
+y; say for @$$y'
1
2
3
REF(0x600003e80)
ARRAY(0x60008a868)
1
2
3
[download]

I suggest you play around with examples like these to get a better understanding of how all of this works.

Also note that I didn't use, or indeed need, terms such as pointer, address or memory location.

You used strict and warnings in your OP which is very good. I suggest you do the same with oneliners. Here's a common alias I use; you might want to set up something similar for yourself (although, perhaps, one a little less involved).

$ alias perle
alias perle='perl -Mstrict -Mwarnings -Mautodie=:all -MCarp::Always -E
+'
[download]

That will pick up things like this:

$ perl -E '$x =5'

$ perle '$x =5'
Global symbol "$x" requires explicit package name (did you forget to d
+eclare "my $x"?) ...

$ perl -E 'my $x = 5; say @$x'

$ perle 'my $x = 5; say @$x'
Can't use string ("5") as an ARRAY ref while "strict refs" in use ...
[download]

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.