symbolize keys for hashes

hash.rb

class Hash
  def symbolize_keys
    self.inject({}) { |acc, elem| acc.merge!(elem[0].to_sym => elem[1]) }
  end
  
  def deep_symbolize_keys
    self.inject({}) do |acc, elem|
      acc.merge! elem[0].to_sym => elem[1].class == Hash ? elem[1].deep_symbolize_keys : elem[1]
    end
  end
end

use_those_methods.rb

hash = {"a" => {"b" => 1}}
p hash.deep_symbolize_keys
# {:a => {:b => 1}}
p hash.symbolize_keys
# {:a => {"b" => 1}}