如何使用 ruby 访问嵌套哈希数组

Question

results = [
   {"day"=>"2012-08-15", "name"=>"John", "calls"=>"5"},
   {"day"=>"2012-08-15", "name"=>"Bill", "calls"=>"8"},
   {"day"=>"2012-08-16", "name"=>"Bill", "calls"=>"11"},
]

我可以使用以下代码访问哈希

results.find {|i| i["day"] == "2012-08-15" and i["name"] == "Bill"}["calls"]

如何在以下代码中访问电子邮件

results = [
   {"name"=>"John", "address"=>{"email"=> "john@example.com"}},
   {"name"=>"Bill", "address"=>{"email"=> "bill@example.com"}},
]

Answer 1

要访问 John 的电子邮件：

results[0]["address"]["email"]
=> "john@example.com"

要打印所有电子邮件：

results.each do |result|
  p result["address"]["email"]
end

Answer 2

results.find {|i| i["name"] == "Bill"}["address"]["email"]

尽管您应该验证结果不为空。

看到这个fiddle

Answer 3

如果

results = [
   {"name"=>"Irma", "address"=>{"email"=> "irma@example.com"}},
   {"name"=>"John", "address"=>{"email"=> "john@example.com"}},
   {"name"=>"Bill", "address"=>{"email"=> "bill@example.com"}},
]

并且您希望今天获取 John 的电子邮件地址，也许明天获取 Irma 的电子邮件地址，您可能希望创建一个新哈希：

addresses = results.map { |h| [h["name"], h["address"]["email"]] }.to_h
  #=> {"Irma"=>"irma@example.com", "John"=>"john@example.com", "Bill"=>"bill@example.com"}

如何使用 ruby 访问嵌套哈希数组

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