title: taking out objects from NSMutableArray
body: <p>I have an array which contains objects some may be same and some are different.<br>
  How can I take each same objects and different objects separately ?</p>
  
  <p>Below is the array</p>
  
  <pre><code>NSMutableArray *items = [[NSMutableArray alloc]
   initWithArray:[NSArray arrayWithObjects:@"rat", @"rat", @"cat",@"Lion", @"cat", @"dog", @"dog", nil]];
  </code></pre>
  
  <p>I want to have four arrays which will contains these items :  </p>
  
  <ul>
  <li>First array with two rats  </li>
  <li>2nd array with  two cats  </li>
  <li>3rd array with one lion  </li>
  <li>4th array with two dogs  </li>
  </ul>
  
  <p>What could be the best way to take the objects out ? Identical object should be placed in same array.</p>