Using perl -MO=Deparse may shed some light on some of this weirdness, although I have no idea why on Earth anyone would implement 'inf' the way it works on my box. 
perl -MO=Deparse -e 'print $n[inf]'

[download]
prints 
print $n[9**9**9];

[download]
as does 
perl -MO=Deparse -e 'print $n["inf"]'

[download]

 

On the other hand, 

perl -MO=Deparse -e 'print $n[-inf]'

[download]
prints 
print $n[-'inf'];

[download]

  

perl -MO=Deparse -e 'print "", inf==0 ? "a" : "b", 'inf'==0 ? "c" : "d
+", -inf==0 ? "e" : "f"'

[download]
prints 
print '', 'inf' == 0 ? 'a' : 'b', 'inf' == 0 ? 'c' : 'd', -'inf' == 0 
+? 'e' : 'f';

[download]

As nearly as I can tell at the moment, inf is only equivalent 9**9**9 if it is used by itself as a subscript; it is taken as a bareword in a simple assignment, so 

perl -MO=Deparse -e '$n[inf], $n[1+inf], $n[-inf] = inf'

[download]
prints 
$n[9**9**9], $n[1 + 'inf'], $n[-'inf'] = 'inf';

[download]

 

My perl -v shows, 

This is perl, v5.8.8 built for i486-linux-gnu-thread-multi

[download]

 

Does anyone know why? - quester

In reply to Re^2: $array[ 'Infinity' ] by quester
in thread $array[ 'Infinity' ] by Sixtease

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.