From: Daniel Bush <dlb.id.au@...>
Date: 2008-08-20T21:58:02+09:00
Subject: Re: array of hashes - need to iterate and calulate stats but how

Adam Akhtar wrote:
> hi lex,
> 
> im not so hot on ruby, could you expand on what you mean by that?

Hi Adam,
I quite like the class and struct approaches already mentioned but I had 
a stab at just using plain arrays and hashes (not extensively tested):

require 'pp'
items = [
  {  :title => 'title1' , :model => '123a' , :sold => false },
  {  :title => 'title2' , :model => '123a' , :sold => false },
  {  :title => 'title3' , :model => '123b' , :sold => true },
  {  :title => 'title4' , :model => '123c' , :sold => false },
  {  :title => 'title5' , :model => '123c' , :sold => true }
]

summary=Hash.new({:listings => 0 , :sold => 0 , :rate => 0})
items.each do |item|
  # Store default value if key in 'summary' doesn't exist.
  summary[item[:model]]=summary.default.clone unless \
    summary.has_key?(item[:model])
  model=summary[item[:model]]

  model[:listings]+=1
  model[:sold]+=1 if item[:sold]
  model[:rate]=model[:sold].to_f/model[:listings].to_f

end

pp summary


Regards,
Daniel
-- 
Posted via http://www.ruby-forum.com/.