Or you can use map although many do not like using map in a void context others find it more intuitive to operate on the entire array than looping through it's elements, Horses for courses. Map is slightly slower than foreach in this sort of case. If speed matters see this Re^4: how to avoid nested looping? for an excellent benchmark of map and for(each)? ). 

my @array = qw/aa bb cc aa cc cc dd aa aa/;
my %sums;
map {$sum{$_}++} @array;
print "$_ = $sums{$_}\n" foreach sort keys %sums;

[download]

Cheers,
R.

Pereant, qui ante nos nostra dixerunt!

In reply to Re: Counting unique elements in an array by Random_Walk
in thread Counting unique elements in an array by Anonymous Monk

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.