Joining arrays of hashes in Ruby

arrays, ruby

Solution

If you put all the different hashes into one array, you can use `group_by` to group together those with the same `country_id`. You can then use `inject` with `merge` to `merge` those together:

country_info_and_stats = country_info + country_stats
country_info_and_stats.group_by {|x| x[:country_id]}.map do |k,v|
  v.inject(:merge)
end
#=> [{:country_id=>"US", :country_desc=>"United States", :pageviews=>150},
#    {:country_id=>"AU", :country_desc=>"Australia", :pageviews=>200}]

Problem

I am trying to join multiple arrays of hashes in ruby using a common key. For example: ``` country_info = [ {country_id: "US", country_desc: "United States"}, {country_id: "AU", country_desc: "Australia"} ] country_stats = [ {country_id:"US", pageviews: 150}, {country_id:"AU", pageviews: 200} ] i_want = [ {country_id: "US", country_desc: "United States", pageviews:150}, {country_id: "AU", country_desc: "Australia", pageviews:200} ] ``` This is something like the pv.nest function of protovis in Javascript. See: http://protovis-js.googlecode.com/svn/trunk/jsdoc/symbols/pv.Nest.html how can I do this in Ruby?

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