Question

我想获取uniq区域并使用“status = stopped”进行过滤。不使用任何循环。可能吗？

散列：

{"a123" => {"status"=>"stopped", "region"=>"US-EAST"},
 "b123" => {"status"=>"stopped", "region"=>"US-EAST"},
 "c123" => {"status"=>"stopped", "region"=>"US-WEST"},
 "d123" => {"status"=>"running", "region"=>"US-WEST"},
 "e123" => {"status"=>"running", "region"=>"US-NORTH"}}

我的过滤状态代码：

hash.select{ |k, v| v["status"] == "stopped" }.values

#=> [{"status"=>"stopped", "region"=>"US-EAST"},
     {"status"=>"stopped", "region"=>"US-EAST"},
     {"status"=>"stopped", "region"=>"US-WEST"}]

我不知道接下来要做什么，我希望输出为：

#=> {"US-EAST", "US-WEST"}

我是红宝石和哈希的菜鸟。请帮忙^ _ ^

Answer 1

hash.map {|_,v| v['region'] if v['status'] == 'stopped'}.compact.uniq
# => ["US-EAST", "US-WEST"]

Answer 2

 hash.select{ |k,v| v["status"] == "stopped" }.values.map { |e| e["region"] }.uniq
=> ["US-EAST", "US-WEST"]

# use `map` method to put region to an array
hash.select{ |k,v| v["status"] == "stopped" }.values.map { |e| e["region"] }
=> ["US-EAST", "US-EAST", "US-WEST"]

#then use the `uniq` method remove repeated.
["US-EAST", "US-EAST", "US-WEST"].uniq
=> ["US-EAST", "US-WEST"]

hash.select{ |k,v| v["status"] == "stopped" }.values.map{ |e| {"region" => e["region"]}}.uniq
=> [{"region"=>"US-EAST"}, {"region"=>"US-WEST"}]

Answer 3

这是另一种方式：

require 'set'

hash.each_with_object(Set.new) do |(_,h),s|
  s << h["region"] if h["status"]=="stopped"
end.to_a
  #=> ["US-EAST", "US-WEST"]

我如何获得此哈希的uniq值？

3 个答案: