From: "David A. Black" <dblack@...>
Date: 2008-08-20T20:32:09+09:00
Subject: Re: array of hashes - need to iterate and calulate stats but how

Hi --

On Wed, 20 Aug 2008, Lex Williams wrote:

> something like this :
>
> statistic_hash = {}
>
> array.each do |hash|
>    if(hash[:did_it_sell)
>        if(statistic_hash.has_key? hash[:title]
>            statistic_hash[hash[:title]] += 1
>        else
>            statistic_hash[hash[:title]]  = 0
>        end
>    end
> end
>
> and then you would have a statistic_hash containing as key a product
> name , and as value , the number of units sold. I'm not sure about how
> to calculate the statistics .

You can use a hash with a default value to make all that hash testing
easier:

   statistic_hash = Hash.new(0)
   array.each do |hash|
     next unless hash[:did_it_sell]
     statistic_hash[hash[:title]] += 1
   end


David

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