From: Phrogz <phrogz@...>
Date: 2010-07-12T22:15:22+09:00
Subject: Re: Arrays and Hashes

On Jul 12, 6:22 am, Abder-rahman Ali <abder.rahman....@gmail.com>
wrote:
> Unlike arrays, the items in a hash are not kept in a specific order.

Note that this is no longer true in Ruby 1.9. Insertion order,
including initialization, is maintained for Hashes:


Slim2:~ phrogz$ irb --simple-prompt
>> h = { a:1, z:7 }
=> {:a=>1, :z=>7}
>> h[:f] = 14; h[:b] = 99
=> 99
>> h['last'] = "this one"
=> "this one"
>> h[-1] = "really last"
=> "really last"
>> h.each{ |k,v| p [k,v] }
[:a, 1]
[:z, 7]
[:f, 14]
[:b, 99]
["last", "this one"]
[-1, "really last"]
=> {:a=>1, :z=>7, :f=>14, :b=>99, "last"=>"this one", -1=>"really
last"}
>> h.keys
=> [:a, :z, :f, :b, "last", -1]