attr_accessor的默认值 [英] attr_accessor default values

问题描述

我正在使用rails，因此我想将其设置为默认情况下将attr_accessor :politics设置为false.

I'm using rails and I want to make it so that attr_accessor :politics is set, by default, to false.

有人知道如何做到这一点，并能为我简单地解释一下吗?

Does anyone know how to do this and is able to explain it in simple terms for me?

推荐答案

Rails具有 attr_accessor_with_default 你可以写

Rails has attr_accessor_with_default so you could write

class Like
  attr_accessor_with_default :politics,false
end

i = Like.new
i.politics #=> false

仅此而已

更新

attr_accessor_with_default 在Rails 3.2中已被弃用.您可以使用纯Ruby

attr_accessor_with_default has been deprecated in Rails 3.2.. you could do this instead with pure Ruby

class Like
  attr_writer :politics

  def politics
    @politics || false
  end
end

i = Like.new
i.politics #=> false

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