我有两个哈希，例如:
{'a' => 30, 'b' => 14}
{'a' => 4, 'b' => 23, 'c' => 7}
其中a、b和c是对象.如何将这些散列的键相加，得到一个新的散列，如:
{'a' => 34, 'b' => 37, 'c' => 7}
我有两个哈希，例如:
{'a' => 30, 'b' => 14}
{'a' => 4, 'b' => 23, 'c' => 7}
其中a、b和c是对象.如何将这些散列的键相加，得到一个新的散列，如:
{'a' => 34, 'b' => 37, 'c' => 7}
a_hash = {'a' => 30, 'b' => 14}
b_hash = {'a' => 4, 'b' => 23, 'c' => 7}
a_hash.merge(b_hash){ |k, a_value, b_value| a_value + b_value }
=> {"a"=>34, "b"=>37, "c"=>7}
b_hash.merge(a_hash){ |k, b_value, a_value| a_value + b_value }
=> {"a"=>34, "b"=>37, "c"=>7}