Question

I have an array of hashes, this is not an active record model. This array is of objects of type Person with properties of id, name, age. I have a second array of strings, ["john", "james", "bill"].

I am attempting to remove all objects in the array of hashes except for the ones who have names in the second array, essentially performing an intersect, but I’m having quite a few problems. Any suggestions? I’m not sure if my syntax is just off or if I’m thinking about this the wrong way. Obviously I can just iterate through but this seems like its probably not the best way to handle the situation.

Answer 1

http://www.ruby-doc.org/core-1.9.2/Array.html#method-i-select

arr1 = [{:id => 1, :name => "John"}, {:id => 2, :name => "Doe"}];
arr2 = ["Doe"];

intersect = arr1.select {|o| arr2.include? o[:name]} # you can also use select!
p intersect # outputs [{:name=>"Doe", :id=>2}]