在Ruby中加入哈希数组

Question

我正在尝试使用公共密钥加入ruby中的多个哈希数组.例如:

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}
]

这类似于Javascript中protovis的pv.nest功能.请参阅:http://protovis-js.googlecode.com/svn/trunk/jsdoc/symbols/pv.Nest.html

我怎么能在Ruby中做到这一点？

Answer 1

如果将所有不同的哈希值放在一个数组中,则可以将group_by它们组合在一起使用相同的哈希值country_id.然后,您可以使用inject与merge向merge那些一起:

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}]