title: How do I add a new attribute to each ActiveRecord in array based on value from another array?
body: <p>as always you are irreplaceable when it comes to help. I got a new problem.</p>
  
  <p>I have two Models.</p>
  
  <pre><code>User(id: integer)
  Follower(id: integer, source_user_id: integer, target_user_id: integer)
  </code></pre>
  
  <p>I have <code>params[:user_id]</code> input via get.</p>
  
  <p>I need to create an array of records that contains <code>is_following =&gt; true/false</code>. </p>
  
  <p><code>is_following</code> should be true when there is a Follower record present for <code>source_user_id = params[:user_id]</code></p>
  
  <p><code>is_following</code> should be false when there is no Follower record present for this parameter</p>
  
  <p>What is the most efficient way to do this?</p>
  
  <p>Thank you!</p>