Pushing into a hash of arrays

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

Hi, I just got a crush curse in PERL, since I am working on small project. I am not familiar with PERL, but PHP.

I need to push data into the following PERL structure of hash-array combination. Basically I need to read from a spreadsheet values containing 'owner' information and link it to a specific directory. It can be done manually like this:

$directory{"owner1"}{0} = ["DIR1", "DIR2", "DIR3"];
$directory{"owner2"}{0} = ["DIR4", "DIR5", "DIR6"];
[download]

This works, but now I need to read it from the spreadsheet as the values come, and assign it to the specific 'owner' key Is there a way to push into a specific key? i.e:

push @directory{"owner1"} $value
[download]

This way it gets pushed into the specific array. Any help will be greatly appreciated. Thanks in advance.

Comment on Pushing into a hash of arrays Select or Download Code

Replies are listed 'Best First'.
Re: Pushing into a hash of arrays by Arunbear (Prior) on Mar 16, 2015 at 17:25 UTC
There is a way i.e. `push @{ $directory{owner1} }, $value;` [download] or `push @{ $directory{owner1}{0} }, $value;` [download] if there actually is an intermediate hash with key "0" that holds the array (I'm not sure why you need the intermediate hash). Updated: D'oh! Added missing commas in code samples (thanks hdb / choroba / davido !)	[reply] [d/l] [select]
Re^2: Pushing into a hash of arrays by alberto_zurita (Initiate) on Mar 17, 2015 at 19:51 UTC
Thanks to all for you answers! ;)	[reply]
Re: Pushing into a hash of arrays by sapphirecat (Acolyte) on Mar 16, 2015 at 19:45 UTC
Hashes and arrays are different things in Perl. When you write `$directory{"owner1"}{0} = ["DIR1", "DIR2", "DIR3"];` you are assigning a new arrayref to a hashref inside a hash. That is, `%directory = ("owner1" => { "0" => [...] });` and `$directory{"owner1"}{0}[0] eq "DIR1"`. (Note the curly-braces vs. square-brackets for hash/array access.) If you iterate over `keys %{$directory{"owner1"}}` then your keys will show up in an undefined order, not necessarily counting from 0 on up. I think you may need a comma in the push syntax as well as telling Perl you want to access the key as an array. Also assuming that you don't want the numerically-indexed hash in the middle layer, that would be: `push @{ $directory{"owner1"} }, $value;` That's how I always write it, anyway. "Basically, displaying invisible data is not maintainable."	[reply] [d/l] [select]
Re: Pushing into a hash of arrays by crusty_collins (Friar) on Mar 16, 2015 at 18:50 UTC
if you already have the dirs out can do it like this `use strict; use warnings; use Data::Dumper; my $directory ={}; @{$directory->{owner1} } = qw( dir1 dir2 dir3 ); @{$directory->{owner2} } = qw( dir4 dir5 dir6 ); print Dumper $directory;` [download] ouput `$VAR1 = { 'owner2' => [ 'dir4', 'dir5', 'dir6' ], 'owner1' => [ 'dir1', 'dir2', 'dir3' ] };` [download]	[reply] [d/l] [select]
Re: Pushing into a hash of arrays by Mr. Muskrat (Canon) on Mar 17, 2015 at 18:47 UTC
Hi, I just got a crush curse in PERL “Curse us and crush us, my precious is lost!” ― J.R.R. Tolkien The name of the language is "Perl" with only the first letter capitalized.	[reply]
A reply falls below the community's threshold of quality. You may see it by logging in.