Merging multi-dimensional hashes in Ruby

Question

I have two hashes which have a structure something similar to this:

hash_a = { :a => { :b => { :c => \"d\" } } }
hash_b = { :a => { :b => { :x         


        

Answer 1

You can do it in one line :

merged_hash = hash_a.merge(hash_b){|k,hha,hhb| hha.merge(hhb){|l,hhha,hhhb| hhha.merge(hhhb)}}

If you want to imediatly merge the result into hash_a, just replace the method merge by the method merge!

If you are using rails 3 or rails 4 framework, it is even easier :

merged_hash = hash_a.deep_merge(hash_b)

or

hash_a.deep_merge!(hash_b)