title: Remove the string on the beginning of an URL
body: <p>I want to remove the "<code>www.</code>" part from the beginning of an URL string</p>
  
  <p>For instance in these test cases:</p>
  
  <p>e.g. <code>www.test.com</code> → <code>test.com</code><br>
  e.g. <code>www.testwww.com</code> → <code>testwww.com</code><br>
  e.g. <code>testwww.com</code> → <code>testwww.com</code> (if it doesn't exist)</p>
  
  <p>Do I need to use Regexp or is there a smart function?</p>