title: An efficient way to convert List<Integer> to int[] ( array ) without iteration
body: <pre><code>  public static int[] convertListToArray(List&lt;Integer&gt; listResult) {
          int[] result = new int[listResult.size()];
          int i= 0;
          for (int num : listResult) {
              result[i++] = num;
          }
          return result;
      }
  </code></pre>
  
  <p>Is there an efficient way to convert List to array without iterating List explicitly ? 
  Maybe it is possible by using methods like: </p>
  
  <pre><code>Arrays.copyOf(int [] origin , int newLength );
  System.arraycopy(Object src,  int  srcPos,
                                      Object dest, int destPos,
                                      int length);
  </code></pre>
  
  <p>I know that there is a solution described <a href="https://stackoverflow.com/questions/4042434/converting-arrayliststring-to-string-in-java">here</a>. However, I particularly interested in an efficient way of converting <code>List&lt;Integer&gt;</code> to <code>int[]</code> </p>