title: how to use separator param of print in swift2
body: <p>Sorry for newbee question.</p>
  
  <p>I really do not know how to use separator param in print</p>
  
  <pre><code>var str = "Hello, playground"
  var strs = ["abc","def"]
  
  print(str)
  print(strs, separator: ",", terminator: "")
  print(str, separator: ",", terminator: "\n")
  </code></pre>