title: convert the following code from a for-loop to Array#map
body: <p>i am working on simple js function... 
  I am trying to convert the following code from a for-loop to Array#map
  providing my code below in the fiddle.. 
  bnasically i am trying to learn array map..</p>
  
  <p><a href="http://jsfiddle.net/newtdms2/" rel="nofollow">http://jsfiddle.net/newtdms2/</a></p>
  
  <pre><code>function doubleAll(numbers) {
      var result = [];
      result = numbers.map(function(num) {
          for (var i = 0; i &lt; numbers.length; i++) {
              result.push(numbers[i] * 2)
          }
          return result;
      });
  }
  
  module.exports = doubleAll
  </code></pre>