Find key/value pairs deep inside a hash containing an arbitrary number of nested hashes and arrays

Question

A web service is returning a hash that contains an unknown number of nested hashes, some of which contain an array, which in turn contains an unknown number of nested hashes

Answer 1

Here's a simple recursive solution:

def nested_hash_value(obj,key)
  if obj.respond_to?(:key?) && obj.key?(key)
    obj[key]
  elsif obj.respond_to?(:each)
    r = nil
    obj.find{ |*a| r=nested_hash_value(a.last,key) }
    r
  end
end

h = { foo:[1,2,[3,4],{a:{bar:42}}] }
p nested_hash_value(h,:bar)
#=> 42