Ruby将Object转换为Hash

Question

假设我有&的Gift对象.将它转换为Ruby中的Hash的最佳方法是什么,而不是Rails(尽管也可以自由地给出Rails的答案)？@name = "book"@price = 15.95{name: "book", price: 15.95}

Answer 1

只说(当前对象) .attributes

.attributes返回hash任何一个object.而且它也更清洁.

Answer 2

class Gift
  def initialize
    @name = "book"
    @price = 15.95
  end
end

gift = Gift.new
hash = {}
gift.instance_variables.each {|var| hash[var.to_s.delete("@")] = gift.instance_variable_get(var) }
p hash # => {"name"=>"book", "price"=>15.95}

或者each_with_object:

gift = Gift.new
hash = gift.instance_variables.each_with_object({}) { |var, hash| hash[var.to_s.delete("@")] = gift.instance_variable_get(var) }
p hash # => {"name"=>"book", "price"=>15.95}

Answer 3

实施#to_hash？

class Gift
  def to_hash
    hash = {}
    instance_variables.each { |var| hash[var.to_s.delete('@')] = instance_variable_get(var) }
    hash
  end
end


h = Gift.new("Book", 19).to_hash

Answer 4

Gift.new.instance_values # => {"name"=>"book", "price"=>15.95}

Answer 5

你可以使用as_json方法.它会将您的对象转换为哈希值.

但是,该哈希值将作为该对象名称的值作为键.在你的情况下,

{'gift' => {'name' => 'book', 'price' => 15.95 }}

如果需要存储在对象中的哈希值as_json(root: false).我认为默认情况下root将是false.有关更多信息,请参阅官方红宝石指南

http://api.rubyonrails.org/classes/ActiveModel/Serializers/JSON.html#method-i-as_json

Answer 6

对于活动记录对象

module  ActiveRecordExtension
  def to_hash
    hash = {}; self.attributes.each { |k,v| hash[k] = v }
    return hash
  end
end

class Gift < ActiveRecord::Base
  include ActiveRecordExtension
  ....
end

class Purchase < ActiveRecord::Base
  include ActiveRecordExtension
  ....
end

然后打电话

gift.to_hash()
purch.to_hash() 

Answer 7

class Gift
  def to_hash
    instance_variables.map do |var|
      [var[1..-1].to_sym, instance_variable_get(var)]
    end.to_h
  end
end

Answer 8

如果您不在Rails环境中(即没有ActiveRecord可用),这可能会有所帮助:

JSON.parse( object.to_json )

Answer 9

您可以使用功能样式编写非常优雅的解决方案.

class Object
  def hashify
    Hash[instance_variables.map { |v| [v.to_s[1..-1].to_sym, instance_variable_get v] }]
  end
end

Answer 10

使用 'hashable' gem ( https://rubygems.org/gems/hashable ) 将对象递归转换为散列示例

class A
  include Hashable
  attr_accessor :blist
  def initialize
    @blist = [ B.new(1), { 'b' => B.new(2) } ]
  end
end

class B
  include Hashable
  attr_accessor :id
  def initialize(id); @id = id; end
end

a = A.new
a.to_dh # or a.to_deep_hash
# {:blist=>[{:id=>1}, {"b"=>{:id=>2}}]}