如何在 Ruby 中获取类实例? [英] How to get class instances in Ruby?

问题描述

假设我有一个名为 Post 的类，它有许多已启动的实例(即 Post.new(:name => 'foo')).

Say I have a class called Post that has many initiated instances (i.e. Post.new(:name => 'foo')).

有没有办法通过调用某个类来检索该类的所有实例?我正在寻找类似 Post.instances.all

Is there a way to retrieve all the instances of that class by calling something on it? I'm looking for something along the lines of Post.instances.all

想法?

谢谢！

推荐答案

说明 alphazero 和 PreciousBodilyFluids 的答案:

Illustrating both alphazero's and PreciousBodilyFluids answers:

class Foo
  @@instance_collector = []
  def initialize
    @@instance_collector << self
    #other stuff
  end
  def self.all_offspring
    @@instance_collector
  end
end

a = Foo.new
b = Foo.new

p Foo.all_offspring  # => [#<Foo:0x886d67c>, #<Foo:0x886d668>]
p ObjectSpace.each_object(Foo).to_a # => [#<Foo:0x886d668>, #<Foo:0x886d67c>] #order is different

这篇关于如何在 Ruby 中获取类实例?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！