ruby - 如何将多个值推送到同一个哈希键

Question

初学者的问题，请帮帮我

my_array = ["city1:state1","city2:state2","city3:state1","city4:state3","city5:state1"]

我如何从这个数组中生成这样的散列？

{
 state1: [city1,city3,city5],
 state2: [city2],
 state3: [city4]
}

我正在尝试这种方式

my_hash = { }
my_array.each do |cs|
 temp = cs.split(":")
 if my_hash.keys.include? temp[1]
  my_hash[temp[1]] = temp[0]
 else
  my_hash[temp[1]] = temp[0]
 end
end

但我不知道如何匹配我的哈希键并附加到键。

Answer 1

稍微修改一下就可以了:

my_hash = { }
my_array.each do |cs|
 temp = cs.split(":")
 if my_hash.keys.include? temp[1].to_sym
  my_hash[temp[1].to_sym] << temp[0]
 else
  my_hash[temp[1].to_sym] = [temp[0]]
 end
end

结果是 {:state1=>["city1", "city3", "city5"], :state2=>["city2"], :state3=>["city4"]}。我假设这就是您的意思(键是符号，值是字符串数组)。