the first statement takes the elements from the array @keys, increments them and adds to the hash %hash.
first point is, you only have letters, no numbers, so Perl won't "increment" them, and will just add them as they already are to the hash.
secont point, the hash takes two elements to populate a key-value pair. for example, a hash %h = (a => 1, b => 2, c => 3) could also be written as %h = qw{a 1 b 2 c 3}.
the second statement takes each element from the array as a key of the hash, incrementing its value each time it's processed (which means if you have twice the element "a" in the array, the value of the key "a" in the hash will be 2 etc). if you want to use map to do that, it'd like map { $hash{$_}++ } @keys.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*women.pm

In reply to Re^3: Hash assignments using map by mk.
in thread Hash assignments using map by njcodewarrior

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.