Beefy Boxes and Bandwidth Generously Provided by pair Networks
Syntactic Confectionery Delight

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??


I like to invert the hash for things like this. This way, you get a list of the keys for each value:

$ cat #!/usr/bin/perl my %hash = (key1=>10,key2=>10,key3=>3,key4=>5,key5=>10); my %invhash; while (my ($k,$v) = each %hash) { push @{$invhash{$v}}, $k; } for my $v (sort {$a<=>$b} keys %invhash) { print "$v cnt=", scalar(@{$invhash{$v}}), " keys=",join(", ",@{$invhash{$v}}), "\n"; } $ perl 3 cnt=1 keys=key3 5 cnt=1 keys=key4 10 cnt=3 keys=key5, key2, key1

But if you don't find the list of keys useful, or if there's too much data, just incrementing a counter as you suggest will do the job.


When your only tool is a hammer, all problems look like your thumb.

In reply to Re: How to compare hash values within the same hash? by roboticus
in thread How to compare hash values within the same hash? by phildeman

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, 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, 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.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others meditating upon the Monastery: (5)
    As of 2015-11-26 19:34 GMT
    Find Nodes?
      Voting Booth?

      What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

      Results (706 votes), past polls