title: Passing in an array into form_for() and link_to()
body: <p>I am reading Rails 3 In Action.  The book builds a class of Projects which <code>has_many :tickets</code> and a class of Tickets which <code>belongs_to :project</code>.  The routes.rb file looks like this:</p>
  
  <pre><code>    resources :projects do
        resources :tickets
      end
  </code></pre>
  
  <p>Now the form for creating a ticket takes in an array like so:</p>
  
  <pre><code>    &lt;%= form_for [@project, @ticket] do |f| %&gt;
  </code></pre>
  
  <p>And on the ticket show.html.erb page there are links which look like this:</p>
  
  <pre><code>    &lt;%= link_to "Edit Ticket", [:edit, @project, @ticket] %&gt;
      &lt;%= link_to "Delete Ticket", [@project, @ticket], :method =&gt; :delete,
      :confirm =&gt; "Are you sure you want to delete this ticket?" %&gt;
  </code></pre>
  
  <p>Now I'm confused why the array of the two objects needs to be passed into form_for() and into link_to().  Also, why does "Edit Ticket" require and :edit symbol while "Delete Ticket" does not require a :destroy symbol.</p>
  
  <p>thanks,
  mike</p>