It seems to me that the first and second code paragraphs below should behave identically, and the third should behave nearly identically (except that it increments only once). As shown, the behaviour is quite different (on Perl 5.10.1 and, with the obvious modification, Perl 5.8.9). Am I missing something obvious? 

$_ = 'a';
$_++ and say; # => 'b'
$_++ and say; # => 'c'

$_ = 'a';
$_++ and say for 1..2; # => '2', '3'

$_ = 'a';
$_++ and say for 1; # => Modification of a read-only value attempted

[download]

UPDATE: Oops, for aliases $_, so I'm not aliasing incrementing the $_ that I think I'm aliasing incrementing. Sigh, sorry ….

In reply to Auto-incrementing strings in for loops by JadeNB

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.