Ruby:IF 语句中的 Nils [英] Ruby: Nils in an IF statement

问题描述

我正在开发的 Rails 应用中有以下非常难看的 ruby​​ 代码:

I have the following very ugly ruby code in a rails app I'm working on:

if params.present?
  if params[:search].present?
    if params[:search][:tags_name_in].present?
      ...
    end
  end
end

我想问的是 params[:search][:tags_name_in] 是否已定义，但因为 params、params[:search] 和 params[:search][:tags_name_in] 可能都为零，如果我使用...

All I'm trying to ask is whether params[:search][:tags_name_in] has been defined, but because params, and params[:search], and params[:search][:tags_name_in] might all be nil, if I use...

if params[:search][:tags_name_in].present?

...如果没有参数或没有搜索参数，我会收到错误消息.

... I get an error if there are no params or no search params.

当然必须有更好的方法来做到这一点...建议??

Surely there must be a better way to do this... suggestions??

推荐答案

如果您只是想看看它是否已定义，为什么不保持简单并使用已定义的?功能?

if you are just trying to see if its defined why not keep it simple and use the defined? function?

if defined?(params[:search][:tags_name_in])

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