Initializing Instance Variable as an Array - Ruby

问题

I'm trying to initialize and instance variable as an array as follows:

  class Arch < ActiveRecord::Base  
  attr_accessor :name1

    def initialize
      @name1 = []
    end

    def add_name1(t)
      @name1 << t
    end

  end

When I try Arch.new in a console session I get (Object doesn't support #inspect). What's up? How do I make an instance array variable? I tried to follow this like so:

class Arch < ActiveRecord::Base
attr_accessor :name1

  def after_initialize
    @name1 = []
  end

  def add_name1(t)
    @name1 << t
  end

end

and my @name1 was still a NilClass. :/

回答1:

You are overriding ActiveRecord's initialize method. Try using super:

def initialize(*args, &block)
   super 
   @name1 = []
end

回答2:

You are overiding the initialize method of ActiveRecord::Base. When creating a new instance of your class only your initilize will be called. All the instance variables that ActiveRecord::Base would have created are uninitialized and #inspect fails. In order to fix this you need to call the constructor of your base class (using super)

class Arch < ActiveRecord::Base  

  attr_accessor :name1
  def initialize
    super
    @name1 = []
  end

  def add_name1(t)
    @name1 << t
  end
end

来源：https://stackoverflow.com/questions/8072952/initializing-instance-variable-as-an-array-ruby