title: Filter Array with dictionaries using NSPredicate
body: <p>There is an Array with each element being a <code>NSDictionary</code>.</p>
  
  <pre><code>NSMutableArray *mutArr = [NSMutableArray array];
  
  for (Person *person in persons) {
      NSDictionary *dict = [[NSDictionary alloc] initWithObjectsAndKeys:person.name, @"name", person.email, @"email", nil];
      [mutArr addObject:dict];
  }
  
  self.arr = [[NSArray alloc] initWithArray:mutArr];
  </code></pre>
  
  <p>How to filer the <code>arr</code> with name or email contains string <code>@"filter string"</code> by using <code>filterArrayUsingPredicate:</code> method.</p>
  
  <p>Thanks in advance!</p>