可能檢索哪個單例類附加到的實例的值？

Question

這裏是單例類的一個例子：

class MyPost < ActiveRecord::Base 
    def initialize(title) 
    @title = title 
    end 
end 

post = MyPost.new(:title => 'post title') 

def post.some_method 
    #is it possible to retrieve value of `post`? 
    my_post_title = post.title #???. Not working now 
end 

是否有可能重提post在def post.some_method？

Answer 1

有錯誤：在標題 1.無休止單引號。 2.當你在裏面post那麼你可以直接訪問@title，你不能把它post.title

class MyPost < ActiveRecord::Base 
    def initialize(title) 
    @title = title 
    end 
end 

post = MyPost.new(:title => 'post title') 

def post.some_method 
    my_post_title = @title 
end 

post.some_method 

，或者如果您已經從設置你的attr_accessor爲您title

require 'active_record' 

class MyPost < ActiveRecord::Base 
    attr_accessor :title 
    def initialize(title) 
    @title = title 
    end 
end 

post = MyPost.new(:title => 'post title') 

def post.some_method 
    my_post_title = title 
end 

Answer 2

是的。內的方法，該特殊變量self保持對所述消息的接收器的引用：

class MyPost < ActiveRecord::Base 
    def initialize(title) 
    @title = title 
    end 
end 

post = MyPost.new(title: 'post title') 

def post.some_method 
    my_post_title = title 
end