Updated Hashes & Arrays

Bugorr has asked for the wisdom of the Perl Monks concerning the following question:

Thank you everyone for your replys - they were very helpfull, its partially solved the mystery, but not completely!!!
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!!!

Edited by Chady -- added code tags.

Comment on Updated Hashes & Arrays Select or Download Code

Replies are listed 'Best First'.
Re: Updated Hashes & Arrays by davidrw (Prior) on Aug 29, 2005 at 21:19 UTC
`push @{$subjects{$subject}}, %info;` [download] The elements of the array need to be hashrefs, so do this instead: `push @{$subjects{$subject}}, \%info; print "email: " . $subjects{$subject}->[0]->{email};` [download] Please `use strict;` and `use warnings` .. the line `my @ar = @{subjects{$key}};` is missing a "$" .. also note you can write that output as: `foreach my $key (sort (keys %subjects)){ print "\n\nKEY = $key"; print "\nSize of Array = " . scalar @{$subjects{$key}}; }` [download]	[reply] [d/l] [select]
Re: Updated Hashes & Arrays by shemp (Deacon) on Aug 29, 2005 at 21:12 UTC
Your code is nearly impossible to read. Please use CODE tags in your post, and a reasonable indentation scheme. One apparent problem outside of that, you say $subject is an array. You probably mean arrayref, but anyway using an arrayref as a hash key works, but probably doesnt give you the results you're looking for. I use the most powerful debugger available: print!	[reply]


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