ruby-on-rails - rails/ruby 合并两个具有相同键、不同值的散列

Question

我有两个要合并的散列。它们看起来像这样:

[{"Hello"->"3"},{"Hi"->"43"},{"Hola"->"43"}]

第二个哈希看起来像:

[{"Hello"->"4"},{"Hi"->"2"},{"Bonjour"->"2"}]

我想合并这两个哈希数组，结果如下:

[{"Hello"->[{value1=>3},{value2=>4}],{"Hi"->[{value1=>43},{value2=>2}]},{"Bonjour"->[{value1=>0},{value2=>2}]},{"Hola"->[{value1=>43},{value2=>0}]]

是否有一种简单的方法来合并这两个散列，或者我是否必须单独遍历散列并在另一个散列中找到该键？

Answer 1

最简单的方法是将散列数组转换为散列:

h1 = a1.reduce(&:merge)
# => {"Hello"=>"3", "Hi"=>"43", "Hola"=>"43"}
h2 = a2.reduce(&:merge)
# => {"Hello"=>"4", "Hi"=>"2", "Bonjour"=>"2"}

然后你需要找到所有的键:

 keys = [h1, h2].flat_map(&:keys).uniq
 # => ["Hello", "Hi", "Hola", "Bonjour"]

接下来，为每个键构建值数组:

keys.map do |k| 
  {k => [{value1: h1[k] || "0"}, 
         {value2: h2[k] || "0"}]}
end
# => [{"Hello"=>[{:value1=>"3"}, {:value2=>"4"}]}, 
#     {"Hi"=>[{:value1=>"43"}, {:value2=>"2"}]}, 
#     {"Hola"=>[{:value1=>"43"}, {:value2=>"0"}]}, 
#     {"Bonjour"=>[{:value1=>"0"}, {:value2=>"2"}]}]