title: What does the equal ('=') symbol do when put after the method name in a method definition?
body: <p>I saw this in a screencast and was just wondering what the '=' symbol does in this case.</p>
  
  <pre><code>def express_token=(token)
  ...
  end
  </code></pre>
  
  <p>I would understand if it were something like this - </p>
  
  <pre><code>def express_token(token = nil) 
  </code></pre>
  
  <p>The above (second code snippet) means setting nil as the default value of the tokens parameter. However, in the first code snippet, '=' is outside the brackets.</p>