title: Plain functions (outside of a class) in Swift
body: <p>When using Swift, up to now, I am always dealing with classes and their methods.
  Is it also possible to have plain functions outside of any class, and group them together in a file MyFunctions.swift?</p>
  
  <p>I would be surprised if the answer was not YES.</p>
  
  <p>But since what I tried failed, I would like to know how I can refer to this file and its functions when I need it.</p>
  
  <p><code>import MyFunctions.swift</code> did not work.</p>