In the problem I had, I had 2 references that I needed to know if I had already tested them, and what the result is. The first thing that came to mind was using the hash. The problem is that you don't know if refA or refB is the first key into the hash, so you have to test both.

if( $tests{ $refA, $refB } 
      or $tests{$refB, $refA} ) {
   # some stuff
}
# as opposed to
if( $tests{ $refA, $refB} ) { # order not important
   # some stuff
}

[download]

The reason for using the tied interface instead of verbosely writing out the sort join, is so that you don't have to see that extra code, which doesn't add to the understanding of the code, but instead clouds it.

In reply to Re^2: Multiple Unordered Hash Keys by neosamuri
in thread Multiple Unordered Hash Keys by neosamuri

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.