title: Array.map doesn't seem to work on uninitialized arrays
body: <p>I'm trying to set default values on an uninitialized array using the map function but it doesn't seem to work, any ideas on how to set default values?</p>
  
  <p>Consider this code snippet I tried in Chrome console.</p>
  
  <pre><code>&gt; var N = 10;
  &gt; var x = new Array(N);
  &gt; x
    [undefined x 10]
  
  &gt; x.map(function(i) { return 0;});
    [undefined x 10]
  </code></pre>
  
  <p>I was expecting the array to be initialized to 0's.</p>