title: JSON returns empty when data contains special characters
body: <p>I am trying to show data from my database with JSON. But I have some issues with 'special characters'.</p>
  
  <p>The data contains characters like: 'ë'. When I try to show the data, json returns an empty table.</p>
  
  <p>Does someone know how I can fix this issue?</p>
  
  <p>I am trying to show the data with the following code:</p>
  
  <pre><code>echo json_encode($json_data); 
  </code></pre>