Re^2: Copying a hash to an array of hashes.

Thanks for your reply.

It's true, you're right. But why? I looked in my trusty Ellie Quigley, and maybe I wasn't looking in the right place, but I couldn't see anything there.

I would expect this to provide an array of references, but it doesn't.

Anyway it works.

Thanks.

Comment on Re^2: Copying a hash to an array of hashes.

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Re^3: Copying a hash to an array of hashes. by Joost (Canon) on Sep 18, 2009 at 23:41 UTC
Perl references are a bit unintuitive, especially when combined with list context. The main problem you're running into is that putting a hash in list context gives you a flat list containing the keys and values of the hash interleaved, so: `my %array = ( a => 1, b => 2); my @list = %array;` [download] Now @list () will contain either `('a',1,'b',2)` or `('b',2,'a',1)` Just like `my @list1 = (1,2); my @list2 = (@array,3,4);` [download] @list2 will contain (1,2,3,4). But references will not be subject to flattening. I strongly recommend the Camel book for anyone interested in the truth on perl, straight from the horse's mouth. Especially if they're already past the easy stuff. It's not the easiest book but it reads well and for an all round reference and "concept" book on perl, you can't beat it. () please don't ask me about the differences between lists and arrays, it's subtle. forget it for now. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l] [select]

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Re^3: Copying a hash to an array of hashes.
by Joost (Canon) on Sep 18, 2009 at 23:41 UTC

The main problem you're running into is that putting a hash in list context gives you a flat list containing the keys and values of the hash interleaved, so:

my %array = ( a => 1, b => 2);
my @list = %array;
[download]

('a',1,'b',2)

('b',2,'a',1)

Just like

my @list1 = (1,2);
my @list2 = (@array,3,4);
[download]

But references will not be subject to flattening.

I strongly recommend the Camel book for anyone interested in the truth on perl, straight from the horse's mouth. Especially if they're already past the easy stuff. It's not the easiest book but it reads well and for an all round reference and "concept" book on perl, you can't beat it.

(*) please don't ask me about the differences between lists and arrays, it's subtle. forget it for now.

"What should it profit a man, if he should win a flame war, yet lose his cool?"

[reply]
[d/l]
[select]