Thank you everyone for your replys - they were very helpfull, but did not solve my problem!!!
Here's a little more detailed explanation:

I need to read a file (line by line of course).
Line looks like that "subject^email^timestamp"

After file is read I need to do Insertion into database. Now, subjects could be the same and I decided to create this datastructure:
%subjects{$subject}{%hash => email, timestamp} (hope it's clear so far)
%subjects is hash, which has "subject" as a key
$subject is array, which holds hashes or emails and times

So, I created this code:
my %subjects;

foreach my $subm(@subm){
        ($subject, $email, $time) = split(/^/, $subm);


        my %info;
        $info{email} = $email;
        $info{time} = $time;

        if(! exists $subjects{$subject}){
                print "Key DOES NOT exist\n";
                $subjects{$subject} = [];
        }else{
                print "KEY DO EXIST\n";
        }

        push @{$subjects{$subject}}, %info;

}

[download]

I have this code to check that everything is correct: 
foreach my $key (sort (keys %subjects)){

        print "\n\nKEY = $key";
        my @ar = @{subjects{$key}};
        my $size = @ar;
        print "\nSize of Array = $size";
}

[download]

Unfortunately, Size gives me size =1 , which is not true. Please tell me if I am doing something wrong....

Thank you very much!!!

code tags by holli

In reply to Hashes & Arrays by Bugorr

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.