title: How to sort a list in Scala by two fields?
body: <p>how to sort a list in Scala by two fields, in this example I will sort by lastName and firstName?</p>
  
  <pre><code>case class Row(var firstName: String, var lastName: String, var city: String)
  
  var rows = List(new Row("Oscar", "Wilde", "London"),
                  new Row("Otto",  "Swift", "Berlin"),
                  new Row("Carl",  "Swift", "Paris"),
                  new Row("Hans",  "Swift", "Dublin"),
                  new Row("Hugo",  "Swift", "Sligo"))
  
  rows.sortBy(_.lastName)
  </code></pre>
  
  <p>I try things like this </p>
  
  <pre><code>rows.sortBy(_.lastName + _.firstName)
  </code></pre>
  
  <p>but it doesn't work. So I be curious for a good and easy solution.</p>