Extract Values and Keys from Nested Hash

extract_uniq_keys.rb

test_hash = {
  a: 1,
  b: 2,
  c: {
    d: 4,
    e: 5,
    a: 1
  }
}

# We want to extract all uniq keys found in "my_hash"
# for this recursive method, we need to add an accumulator, "founded_keys" that
# will store all keys we found
def extract_keys_from_hash(my_hash, founded_keys = [])
  my_hash.each do |key, value|
    # Add the founded key in the accumulator
    founded_keys.push(key)

    if value.is_a?(Hash)
      # Our value is a Hash, so there is keys to be found !
      # the method call itself to extract the keys in "value" and add them
      # in founded_keys, our accumulator
      extract_keys_from_hash(value, founded_keys)
    end
  end

  # we don't want duplicate keys !
  founded_keys.uniq
end

# should display true 
puts extract_keys_from_hash(test_hash) == [:a, :b, :c, :d, :e]

extract_values.rb

test_hash = {
  a: 1,
  b: 2,
  c: {
    d: 4,
    e: 5,
    a: 1
  }
}

# We want to extract all values found in "my_hash"
# for this recursive method, we need to add an accumulator, "founded_values" tha
# will store all values we found
def extract_values_from_hash(my_hash, founded_values = [])
  my_hash.each do |_key, value|
    if value.is_a?(Hash)
      # value is a hash ! We dont want to add into founded_values !
      # But there is values inside it!
      # So we call "extract_values_from_hash" with value as argument
      # to extract values that are inside "value"
      extract_values_from_hash(value, founded_values)
    else
      # it's not a hash ! So we add it into founded_values
      founded_values.push(value)
    end
  end

  founded_values
end

# should display true 
puts extract_values_from_hash(test_hash) == [1, 2, 4, 5, 1]