title: Json object with dash (-) character on element name
body: <p>I'm parsing a <code>json</code> object that contains an element named <code>data-config</code>.</p>
  
  <p>ex:</p>
  
  <pre><code>var video = data.element.data-config;
  </code></pre>
  
  <p>Whenever I parse this element I'm getting this error:</p>
  
  <pre><code>ReferenceError: config is not defined
  </code></pre>
  
  <p>The <code>ReferenceError</code> doesn't mention <code>data-config</code> but simply <code>config</code>.<br>
  Any idea why I'm getting this error?
  Is this related with the dash (-) character?</p>