title: How to output hidden_field to array?
body: <p>Working on a reply function for basic messaging app, and have been stuck for a while. </p>
  
  <p>In my message controller I'm passing the user_id from the original message author to :to for the reply message":</p>
  
  <pre><code>    @message = current_user.sent_messages.build(:to =&gt; @original.author.id, :subject =&gt; subject, :body =&gt; body)
      render :template =&gt; "sent/raply"
  </code></pre>
  
  <p>My hidden field looks like:</p>
  
  <pre><code>    &lt;%= f.hidden_field :to %&gt;
  </code></pre>
  
  <p>I'm getting the correct user_id passing through the form, but I need the value to be passed as an array like "to"=>["1"], instead of "to"=>"1".</p>