In this example, $item ... wasn't going to used outside of the loop, it should have been declared inside of the loop so that it was destroyed (and the memory it uses freed) when the block exits.

You raise a valid point, but perhaps chose an inappropriate example. Particularly when a block is the body of a loop, you should weight the cost of creating and destroying a loop-scoped lexical variable against the need to keep the memory from being tied up. In this particular (obviously contrived) example, I might leave $item scoped outside the loop if I knew the loop would execute many times, just to avoid the create/destroy cost in terms of execution time and memory fragmentation (which itself might cost execution time later in the program, by slowing down subsequent allocations).

dmm


You can give a man a fish and feed him for a day ...
Or, you can teach him to fish and feed him for a lifetime

In reply to Re(2): where to declare a variable... by dmmiller2k
in thread where to declare a variable... by kiat

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.