ruby-on-rails - 通过哈希值查找哈希数组的交集

Question

例如，如果我有 2 个哈希数组:

user1.id
=> 1
user2.id
=> 2

user1.connections = [{id:1234, name: "Darth Vader", belongs_to_id: 1}, {id:5678, name: "Cheese Stevens", belongs_to_id: 1}]

user2.connections = [{id:5678, name: "Cheese Stevens", belongs_to_id: 2}, {id: 9999, "Blanch Albertson", belongs_to_id: 2}]

那么在 Ruby 中如何通过散列 id 值找到这两个数组的交集？

所以对于上面的例子

intersection = <insert Ruby code here>
=> [{id: 5678, name: "Cheese Stevens"}]

我不能只使用 intersection = user1.connections & user2.connections 因为 belongs_to_id 不同。

谢谢!

Answer 1

就这么简单:

user1.connections & user2.connections

如果你只想通过id键(其他属性不同)

intersection = user1.connections.map{|oh| oh[:id]} & user2.connections.map{|oh| oh[:id]}
user1.connections.select {|h| intersection.include? h[:id] }

希望对您有所帮助!