title: change values in array when doing foreach
body: <p>example:</p>
  
  <pre><code>var arr = ["one","two","three"];
  
  arr.forEach(function(part){
    part = "four";
    return "four";
  })
  
  alert(arr);
  </code></pre>
  
  <p>The array is still with it's original values, is there any way to have writing access to array's elements from iterating function ?</p>