title: Function overloading in PowerShell
body: <p>Can you overload functions in PowerShell?</p>
  
  <p>I want to my function to accept a string, array or some switch.</p>
  
  <p>An example of what I want:</p>
  
  <ul>
  <li>Backup-UsersData singleUser</li>
  <li>Backup-UsersData @('Alice', 'Bob',
  'Joe')</li>
  <li>Backup-UsersData -all</li>
  </ul>