post.rb

class Post
  attr_accessor :title, :body
  @@all = []
  
  def initialize(title, body)
    @title = title
    @body = body
    @@all << self
  end
  
  def self.all
    @@all
  end
  
  def to_s
    "Title: #{@title}, Body: #{@body}"
  end
end