title: How to repeat "key" in ngRepeat one time only (AngularJS)
body: <p>The problem is leaving in the JSON Array response from the Backend/DB. I'm getting the response of the database in the correct json format:</p>
  
  <pre><code>[
    0: {
         "Grade": 100,
         "AB001": 1,
         "AB002": 0,
         "AB003": 9,
         "AB004": 5
       },
    1: {
         "Grade": 98,
         "AB001": 3,
         "AB002": 0,
         "AB003": 0,
         "AB004": 0
       }
  ...
  ] (10 objects as result)
  </code></pre>
  
  <p>Thus displayed in the Firebug console, when you click the Response of the GET Request. To retrieve the keys who are represented in double quotes I've used the ngRepeat directive in my view like following:</p>
  
  <pre><code>&lt;thead&gt;
    &lt;tr ng-repeat="d in data"&gt;
        &lt;th ng-repeat="(key, value) in d"&gt;
            {{key}}
        &lt;/th&gt;
    &lt;/tr&gt;
  &lt;/thead&gt;
  ...
  </code></pre>
  
  <p>Only the problem is, that the key gets repeated 10 times. But I want to repeat the keys one time that means for example the key <code>Grade</code> is only one time in a th-tag and so on..</p>
  
  <p>How can I implement this? I've tried it with angular's <code>forEach()</code> but it wasn't a solution.</p>