title: Scala style: constant map vs pattern matching
body: <p>I need to declare a constant mapping in scala, and wounder what would be the proper way to do that. 
  The Java way is</p>
  
  <pre><code>private static final String[] numbers = {"zero","one","two","three"}  //Java
  val numbers = Array("zero","one","two","three")  //Scala
  val numbers = collection.immutable.HashMap(0 -&gt; "zero", 1 -&gt; "one", 2 =&gt; "two")  //Scala maps
  </code></pre>
  
  <p>Another way to do that in Scala is   </p>
  
  <pre><code> def array(i: Int) = i match {
     case 0 =&gt; "zero"
     case 1 =&gt; "one"
     case 2 =&gt; "two"
  }
  </code></pre>
  
  <p>Is there a standard/recommended way to do it in Scala? </p>