从数组中的对象中删除实例变量

Question

我是Ruby的新手,我只是在玩想法,我想要做的是从我创建的country_array中删除@continent数据.完成了大量的搜索,可以找到有关完整删除元素的相关信息,但无法找到如何专门删除@continent数据.请保持任何答案相当简单,因为我是新的,但任何帮助非常感谢.

class World
  include Enumerable
  include Comparable

  attr_accessor :continent
  def <=> (sorted)
    @length = other.continent
  end

  def initialize(country, continent)
    @country = country
    @continent = continent
  end 
end

a = World.new("Spain", "Europe")
b = World.new("India", "Asia")
c = World.new("Argentina", "South America")
d = World.new("Japan", "Asia")

country_array = [a, b, c, d]

puts country_array.inspect

[#<World:0x100169148 @continent="Europe", @country="Spain">, 
#<World:0x1001690d0 @continent="Asia", @country="India">, 
#<World:0x100169058 @continent="South America", @country="Argentina">, 
#<World:0x100168fe0 @continent="Asia", @country="Japan">]

Answer 1

你可以用remove_instance_variable.但是,由于它是一个私有方法,您需要重新打开您的类并添加一个新方法来执行此操作:

class World
  def remove_country
    remove_instance_variable(:@country)
  end
end

然后你可以这样做:

country_array.each { |item| item.remove_country }
# => [#<World:0x7f5e41e07d00 @country="Spain">, 
      #<World:0x7f5e41e01450 @country="India">, 
      #<World:0x7f5e41df5100 @country="Argentina">, 
      #<World:0x7f5e41dedd10 @country="Japan">]