No, that's incorrect:

use strict;
use warnings;

for my $bool ( 0 .. 1 )
{
    my $name = 'bob' if $bool;
    print "($name)\n";
}

[download]

The actual truth of the matter is that my has compile-time and run-time effects.

At compile time, Perl creates an entry for $namedisplay in the appropriate lexical pad. Thus every lookup for that variable will find the lexical.

At run time, Perl evaluates the condition to determine whether to assign a new value to the lexical variable. Perl doesn't (always) clear lexical variables with refcounts of zero at scope exit (it's an optimization). However, if you don't always reset your variable -- if the run-time behavior of my doesn't occur because of a false conditional -- you will (may) see the old values.

Update: Actually, I can't recreate the memory or trip the warning about it now either, so I've edited my post somewhat.

In reply to Re^2: will you explain what's going on? by chromatic
in thread will you explain what's going on? by maard

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.