Merge an array of hashes that have the same key but different value and add the value

Question

Hello i have a hash that loos similar to this

@receivers
=> [{:amount=>50, :email=>"user_02@example.com"},
 {:amount=>50, :email=>"user_02@example.com"},
 {:amount=>50, :email=>"user_02@example.com"},
 {:amount=>100, :email=>"user_01@example.com"},
 {:amount=>100, :email=>"user_01@example.com"}]

How do i make it look like this?:

@receivers
=> [{:amount=>150, :email=>"user_02@example.com"}
 {:amount=>200, :email=>"user_01@example.com"}]

Thank you for your help.

Answer 1

You can calculate it like this:

@receivers.group_by { |e| e[:email] }
          .map { |k, v| { amount: v.sum { |e| e[:amount] }, email: k } }



#=> [{:amount=>150, :email=>"user_02@example.com"},
#    {:amount=>200, :email=>"user_01@example.com"}]