While it is true that %hash{$_}++ is illegal syntax, it is interesting to note that %hash->{$_}++is not. (But it only works on actual hashes and not hash references.) AFAIK its a bug, but one that has basically become a feature.

use Data::Dumper;
use strict;
use warnings;
my %hash;
%hash->{$_}=$_ foreach 0..5;
print Dumper(\%hash);
__END__
$VAR1 = {
          '0' => 0,
          '1' => 1,
          '2' => 2,
          '3' => 3,
          '4' => 4,
          '5' => 5
        };
[download]

It embarrassed the crap out of me when I discovered this. I was reviewing some code of my colleagues, (relatively new to perl at the time) and identified these as compile time errors. He politely told me what I was full of :-) and then showed me it compiled (and worked) fine. Luckily he had a few other subtle bugs that I found so I managed to avoid looking like a complete moron. :-)

--- demerphq
my friends call me, usually because I'm late....

---

---

• Are you posting in the right place? Check out Where do I post X? to know for sure.
• Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:

  <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>

• Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
• Want more info? How to link or How to display code and escape characters are good places to start.