title: Double Pipe Symbols in Ruby Variable Assignment?
body: <blockquote>
  <p><strong>Possible Duplicate:</strong><br />
  <a href="https://stackoverflow.com/questions/995593/what-does-mean-in-ruby">What does ||= mean in Ruby?</a></p>
  </blockquote>
  
  <p>Forgive me if this is a newbie question but I'm reading a book on rails where the writer used this expression in a helper method:</p>
  <pre><code>@current_user ||= User.find_by_id(session[:user_id])
  </code></pre>
  <p>Is this use of double pipes still a Boolean OR statement?</p>
  <p>If so how does it work?</p>