Some people have already convinced themselves that they know exactly what order things are done and why and even say things like "It must be this way to allow ..."

I don't know how I could have convinced myself I "know exactly what order things are done and why" when I specifically mentioned I didn't know whether execution order is defined in this circumstance.

"It" in "It must be this way to allow ..." refers to passing by reference, not execution order. There is no way of allowing $_[0] = ... to edit the caller's variable without passing the variable in by reference (by definition). Perl5 doesn't currently have a mechanism to specify whether a variable should be passed by value or by reference (or maybe it does and it wasn't used here), so everything must be passed by reference to allow $_[0] = ... to edit the caller's variable.

My post only explains why ++$i affected the $i, nothing more.

In reply to Re^2: Why is the execution order of subexpressions undefined? (why not?) by ikegami
in thread Why is the execution order of subexpressions undefined? by BrowserUk

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.