Ruby on Rails - 从具有特定顺序的现有键的散列数组中获取值数组

Question

原来的数组是这样的：

[{:age=>28, :name=>"John", :id=>1}, {:name=>"David", :age=>20, :id=>2, :sex=>"male"}]

现有密钥的顺序：

[:id, :name, :age] or ['id', 'name', 'age']

结果应该是：

[[1, "John", 28], [2, "David", 20]]

谢谢你教我。

P/s：我正在使用 Ruby 1.8.7 和 Rails 2.3.5

谢谢

Answer 1

映射所有记录，然后按指定顺序映射属性 return 属性值。

records = [
  {:age=>28, :name=>"John", :id=>1},
  {:name=>"David", :age=>20, :id=>2, :sex=>"male"}
]

attributes = [:id, :name, :age]
records.map do |record|
  attributes.map { |attr| record[attr] }
end

Answer 2

这是使用 #values_at 的好方法：

records = [
  {:age=>28, :name=>"John", :id=>1},
  {:name=>"David", :age=>20, :id=>2, :sex=>"male"}
]

attributes = [:id, :name, :age]

records.collect { |h| h.values_at(*attributes) }
# => [[1, "John", 28], [2, "David", 20]]

Ruby on Rails - 从具有特定顺序的现有键的散列数组中获取值数组

Ruby on Rails - Get array of values from array of hash with particular order of existing keys

ruby

arrays

ruby-on-rails

ruby-1.8.7