title: IOS: how to use NSMutableArray
body: <p>In my code, I must to store an array inside another array:
  What's the best way?</p>
  
  <p>first:</p>
  
  <pre><code>NSArray *arrayTemp = myArray;
  </code></pre>
  
  <p>second:</p>
  
  <pre><code>NSMutableArray *arrayTemp = [[NSMutableArray alloc]init];
  [arrayTemp addObjectsFromArray:myArray]; 
  ...instruction....
  [arrayTemp release];
  </code></pre>