undefined method `[]' for nil:NilClass When Looping Through Ruby Array

ruby, ruby-on-rails-3

Solution

It seems you have an object of Postion class assigned to the key :position. So you access title and city through accessor methods and not with `[]`.

<% @positions.each do |job| %>
  <%= job[:position].title %>
  <%= job[:position].city %>
<% end %>

Problem

I have a hash of values that I am trying to loop through to display the values in my view. The hash is set up as: ``` {:position=>#<Position id: 2, user_id: 1, title: "Something", city: "Denver", state: "CO", created_at: "2012-07-06 02:55:42", updated_at: "2012-07-06 02:55:42">, :experience=>[# <Experience id: 4, user_id: 1, position_id: 2, description: "Did some stuff", created_at: "2012-07-02 06:24:33", updated_at: "2012-07-02 06:24:33">, #<Experience id: 6, user_id: 1, position_id: 2, description: "Did other stuff", created_at: "2012-07-02 06:24:33", updated_at: "2012-07-02 06:24:33">]} ``` It is created by taking ActiveRecord results and inserting them into a hash (if you want more details, I am happy to add them). In my view, I attempt to loop through the hash: ``` <% for i in 0..@positions.length %> <%= @positions[i][:position][:title] %> <%= @positions[i][:position][:city] %> <% end %> ``` When I open it in the browser, I get an error `undefined method '[]' for nil:NilClass`. If I only use `@positions[i]`, it will dump out the raw hash (first one, then second, and so on). It's when I add `[:position]`, it doesn't work. I can access the values in the console using `@positions[0][:position][:title]`. When I tried writing the loop in console, I got the same error. I know that `i` is counting because I can have it display the value in the browser and it is working correctly. I have tried using `@positions.each do |job|` but ran into the same error. I tried adding another indices in other places: `@positions[i][:position][0]`. Basically, I have two models: Position and Experience. Experience is a child to Position. I want to get Experience for a given Position but only certain experience like ones that occur within a certain time frame. There is most likely a better approach to this and I just don't know it so I'm open to suggestions. Thanks.

Original source