ruby 为哈希数组设置哈希键

Question

给定以下哈希数组，我如何创建一个以 friend_id 为键并以 dist 为值的新哈希？

results = [
 {"user_id"=>"18", "friend_id"=>"17", "dist"=>"1"},
 {"user_id"=>"18", "friend_id"=>"42", "dist"=>"1"},
 {"user_id"=>"18", "friend_id"=>"43", "dist"=>"1"},
 {"user_id"=>"18", "friend_id"=>"46", "dist"=>"2"}
]

desired_hash = {"17" => "1", "42" => "1", "43" => "1", "46" => "2"}

我试过 map 但值在一个数组中。我也尝试 flatten 结果，但它压平了键而不是值

Answer 1

results.each_with_object({}) { |g,h| h[g["friend_id"]] = g["dist"] }

或

results.each_with_object({}) { |g,h| h.update(g["friend_id"]=> g["dist"]) }