title: Compare 2 nsmutablearray and get different object to third array in ios
body: <p>I want to compare 2 <code>NSMutableArray</code> and  get different object into third <code>Array</code>. How can i do that ?</p>
  
  <p>Array1 can loop object .</p>
  
  <pre><code>Array1 = "a", "b","c","d","a","b","c";
  Array2 = "a", "b", "c";
  </code></pre>
  
  <p>And then result </p>
  
  <pre><code>Array3 = "d";
  </code></pre>
  
  <p>Thanks in advance</p>