From: Jacob Mitchell <jacob.d.mitchell@...>
Date: 2010-07-12T21:35:16+09:00
Subject: Re: Arrays and Hashes

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Arrays have order because each one represents a sequence of objects.  This
guarantees that for a given array you'll get consistent results using the
"each" method:

a = [1,2,3]
a.each {|n| puts n}   #you'll always get 1 2 and 3 in that order

Hashes, on the other hand, are more about letting you map some object, the
key, to another object, the value.  A single hash can have several of these
mappings, but the "order" of the mappings is insignificant and therefore not
necessarily consistent.

{:a => 1, :b => 2, :c => 3} == {:b => 2, :a => 1, :c => 3}   # true

Although all of the the "each" methods provided by a hash ("each",
"each_pair", etc.) return items in a sequence, that sequence isn't
guaranteed to be the same every time.

Hope that helps.

-Jake

On Mon, Jul 12, 2010 at 8:22 AM, Abder-rahman Ali <
abder.rahman.ali@gmail.com> wrote:

> In "Why's poignant guide to Ruby" it mentions the following:
>
> Unlike arrays, the items in a hash are not kept in a specific order.
>
> Can you clarify on this?
>
> Thanks.
> --
> Posted via http://www.ruby-forum.com/.
>
>

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