I'm working with an array of OpenStruct objects which looks like this:
a=[<OpenStruct name="test1", x="6", id="1">,<OpenStruct name="test2", x="5", id="2"><OpenStruct name="test1", x="8", id="3">...] I would like to group the OpenStruct objects having the same name, something like this:
a=[<OpenStruct name="test1",x=["6","8"], id=["1","3"]>,<OpenStruct name="test2", x="5", id="2">] How can I do that?
You could use group_by and map methods. I think the code is self explanatory.
a = [ OpenStruct.new(name: "test1", x: "6", id: "1"), OpenStruct.new(name: "test2", x: "5", id: "2"), OpenStruct.new(name: "test1", x: "8", id: "3") ] a.group_by(&:name).map do |name, as| OpenStruct.new( name: name, x: as.map(&:x), id: as.map(&:id) ) end # => [#<OpenStruct name="test1", x=["6", "8"], id=["1", "3"]>, #<OpenStruct name="test2", x=["5"], id=["2"]>] Something like this should work:
a = [ OpenStruct.new(name: "test1", x: "6", id: "1"), OpenStruct.new(name: "test2", x: "5", id: "2"), OpenStruct.new(name: "test1", x: "8", id: "3") ] a.each_with_object({}) { |o, h| h[o.name] ||= OpenStruct.new(name: o.name, x: [], id: []) h[o.name][:x] << o.x h[o.name][:id] << o.id }.values #=> [#<OpenStruct name="test1", x=["6", "8"], id=["1", "3"]>, #<OpenStruct name="test2", x=["5"], id=["2"]>] Note that the x and id attributes for test2 are also converted to arrays. This is usually preferred.
It might be good idea to rename the attributes to indicate an array, i.e. ids instead of id.
groupBy? It seems useful :-)groupBygroups the elements, not their attributes.