title: How to update a dataLayer variable?
body: <p>We initially push an object containing variables to the dataLayer:</p>
  
  <pre><code>dataLayer.push({
      'environment': {
          'userName': 'abc',
          'id': 123,
          'clicks': 0
      }
  });
  </code></pre>
  
  <p>We now want to increase the value of <code>environment.clicks</code> with every click a user makes.
  How to do that? When we push it via</p>
  
  <pre><code>dataLayer.push({
      'environment': {
          'clicks': 123
      }
  });
  </code></pre>
  
  <p>The dataLayer Array may get 10.000s of entries. How to properly update the variable?</p>