title: Extracting Email Domain in Swift/Myplayground
body: <p>I'm compartmentalizing users on firebase according to their email domain. What universal code can I use to extract only 'havard' in the following examples? All user emails end in '.edu'</p>
  
  <p>let email = jsmith@student.havard.edu ,
  let email = jsmith@havard.edu</p>