Hash of a nArray and all that comes with it.

[kingram]

Srsly. I'm not a n00b.
But This has thing has me scrambled.
An hour in and I'm flustered and no google searching or "Perl By Example" reading is helping.
I know it's something really freaking stoopid but c'mon. I think maybe I'm just tired.
Ok anyway here it is:

%entry = {$item_id=>\@data, $item_id=>\@data.....etc}

%entry is a hash populated by a foreach loop that runs through a set of about 200 items, breaking them apart for atomicity of the data (is that a real word I used just there?)

for my $key (sort keys %entry) {
#print Dumper($entry{$key}[1]);
my @entry;
        for (my $i = 0; $i <= $#entry; $i++){
          print $key, " ========================= \n";
          for (my $j =0; $j <= 10; $j++){
            print "Entry[$i][$j] = $entry[$i][$j] \n";
          }
        }
}

As long as I give an explicit value for $j's range, the output is fine. But I cannot figure out how to access the arraysize for $entry[$i]

And if there is a simpler way to do this that I could implement with my limited expertise in perl I'd love to hear some ideas.

Thanks!

[moritz]

%entry = {$item_id=>\@data, $item_id=>\@data.....etc}

I hope that's not what you're doing, because that assigns a hash reference to a hash without dereferencing.

As long as I give an explicit value for $j's range, the output is fine. But I cannot figure out how to access the arraysize for $entry[$i]

my $len = scalar @{ $entry{$key}[$i]  }

gives you the length of the $i array stored at $key.

And I think you're missing the part of your code where you assign to @entry, I can't see how you'll get any output like this. @entry = @{ $entry{$key} } should fix it.

[kingram]

This is how %entry is being populated in the foreach loop:


@update = ($id, $title, $foo, $bar, $baz);
$entry{$file_num} = \@update;

[aitap]

First of all, as it was pointed above, you should either create a reference to a hash (my $reference = { ... }) or just a hash (my %hash = ( ... )), note the brackets.

Next, contents of hash should be accessed using curly, not square brackets (the second is also possible because hashes can be treated as arrays). Example:

my %entry = ($item_id=>\@data, $item_id=>\@data);
print $entry{$i}->[$j]; # contents of the hash ({}) are array referenc
+es; we use -> to work with references; then we use [] to work with ar
+rays
# OR:
my $reference = {$item_id=>\@data, $item_id=>\@data};
print $entry->{$i}->[$j];
# firstly, $entry is a reference to a hash, use ->
# secondly, hash contents are accessed using {}
# thirdly, it's again a reference
# fourthly, arrays are accessed using []

Next, there is a special syntax to treat a variable as a reference: you can always use an array reference, in curly braces, in place of the name of an array. To get the index of an array by its reference, write $# and then write the reference in curly brackets:

my $index = $#{$entry{$i}};

See perlreftut for more.

[2teez]

this:

%entry = {$item_id=>\@data, $item_id=>\@data.....etc};

should be written as either:

$entry = {$item_id=>\@data, $item_id=>\@data,.....etc};
## or
%entry = ($item_id=>\@data, $item_id=>\@data,.....etc);

[kingram]

Isn't ##or what I wrote? Or did you mean that to be something else?

[kingram]

Nevermind. Was hard to see the braces vs parens.

[kingram]

Ok. You wanna hear something REALLY stoopid?
No. Really.
In my life as a programmer, the wrench that I consistently thrown in my own work is phenomenal.
Ok. Here it is:
I've been trying to get a scalar from $#{entry{$key}}
The problem is, that's not the same as $#{$entry{$key}}
I am such a Rookie!
Thanks for the 2nd, 3rd, 4th and 5th pair of eyes folks.
Happy programming!