There are a couple of things going on here. The first is the question of why you should pass variables to a sub instead of using globals, or lexicals that are in the same scope as the sub. The answer is simply that it's easier to see what's going on. The passing of the variable -- and the acceptance of the variable in the sub by reading @_ -- is a kind of documentation, showing what that sub expects. This is standard programming technique stuff. (There's also an issue of creating closures, but that's a little more information than you need right now.)

The other part is whether or not you should pass references. You probably shouldn't when passing scalars, unless they're huge, but all other types are safer and more efficient when passed as references. See the various documentation sources on references for more explanation on that.

---

---

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.