I assume what raybies was referring to was that unless $a is within a scope that encloses the subroutine (which it is in your case but may not necessarily be in the OP's case) then it *can* be modified without having to return it.

However, in my experience, having been bitten way too many times by not paying attention to scopes and mis-using "global variables", in my humble opinion, it is much, much better to be careful and discipline oneself to think of it more along the lines as raybies posed it by keeping things more encapsulated and planning for the variable to be local to the subroutine and then explicitly returning values that you want to change...or to at least be clearer, through the use of references as some of the other responders suggested, that you are doing the change.

But that is just my opinion and certainly your comment is, to the best of my knowledge, right.

ack Albuquerque, NM

In reply to Re^3: Bit operation by ack
in thread Bit operation by toren

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.