From: Bertram Scharpf <lists@...>
Date: 2009-09-22T01:30:04+09:00
Subject: Re: Hash or array?

Hi,

Am Dienstag, 22. Sep 2009, 01:05:12 +0900 schrieb Ne Scripter:
> I have a question, I want to store some data in two columns, for example
> 
> 0001, stuff1 stuff2
> 0002, morestuff
> 0003, extrastuff
> 0004, more evenmore
> 
> I initially thought to use a hash, but it scrambles the order of the
> data so was unsure of its efficiency and use.

Be aware that Array alway assigns all members from [0] to [max].

  a = []
  a[5] = :five
  a               #=> [nil, nil, nil, nil, nil, :five]

To keep the order in Hashes, sort the keys:

  h = { 1 => :a, 2 => :b }
  h.keys.sort { |k| h[ k] ... }
    # or even
  h.sort.each { |k,v| ... }

In Ruby 1.9 the order will be preserved, so just assign
ascendingly.

Bertram


-- 
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de