title: Swift get file extension from web link
body: <p>I have web link, that is something like:</p>
  
  <pre><code>http://hr-platform.nv5.pw/image/comp_1/pdf-test.pdf
  </code></pre>
  
  <p>It may vary in text or extension. What i want is, get "pdf" string and woule be nice to have name of file, which is in that case - "pdf-test".</p>
  
  <p>How to get those strings from web link? Thanks.</p>