You need to quote them explicitly so they are never tested as numbers. The fat comma stringification comes after numeric interpretation and before keyword recognition. I believe the details should be in toke.c in the root of the perl source distrubution.

(Added) Another few examples, 

$ perl -Mstrict -we'BEGIN {$_="foo";} sub bar () {"quux"} my %foo = ( 
+1e0 => "foo", bar => "quux", length => "baz");print "@{[keys %foo]}",
+ $/'
length bar 1
$

[download]
That shows numeric interpretation, then fat comma stringification, then keywords and subs. If keywords had been interpreted, the "length" key would have been "3" instead. If constant subs had been interpolated before, "bar" key would have been "quux".

After Compline,
Zaxo

In reply to Re: Use of the => operator by Zaxo
in thread Use of the => operator by roju

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.