Find keep duplicates in Ruby hashes

Question

I have an array of hashes where I need to find and store matches based on one matching value between the hashes.

a = [{:id => 1, :name => \"Jim\", :em         


        

Answer 1

I tested this and it will do exactly what you want:

b = a.group_by { |h| h[:name] }.values.select { |a| a.size > 1 }.flatten

However, you might want to look at some of the intermediate objects produced in that calculation and see if those are more useful to you.