title: How to get all types of file extensions in array?
body: <p>How to get all types of file extensions which supports the <code>macOS</code> or <code>iOS</code>?<br>
  I am statically defining the <code>extensions</code> as below, but I don't wanna do in this way.
   If Apple introduces the new <code>extension</code> i should get dynamically all the <code>extensions</code>. how to achieve this?</p>
  
  <pre><code>let fileExtensions = ["png", "jpg", "gif","jpeg","tif","mp4","mkv","mov", "zip" ,"txz"]
  </code></pre>
  
  <p>Any Suggestions?</p>
  
  <p>Thanks in Advance !!</p>