title: mutating method sent to immutable object' in nsmutablearray
body: <p>I want to remove objects from NSmutableArray can one tell me the Best way to remove from NSMutableArray </p>
  
  <p>.h</p>
  
  <pre><code>@property(nonatomic,retain)NSMutableArray *arr_property;
  </code></pre>
  
  <p>.m</p>
  
  <pre><code>_arr_property=[[NSMutableArray alloc]init];
  MTPop *lplv = [[MTPop alloc] initWithTitle:SelectProperty(APP_SHARE.language)
                                     options:[_arr_property valueForKeyPath:@"property_list.property_type_name"] 
                                     handler:^(NSInteger anIndex) {
      txt_Property.text=[[_arr_property valueForKeyPath:@"property_list.property_type_name"] objectAtIndex:anIndex];
      NSLog(@"index number %ld",(long)anIndex);
  </code></pre>
  
  <p>remove object--->>></p>
  
  <pre><code>NSLog(@"index number %@",[_arr_property valueForKey:@"property_list"]);
  [[_arr_property valueForKeyPath:@"property_list.property_type_name"] removeObjectAtIndex:anIndex];  ////hear the app is crashing
  </code></pre>
  
  <p>app is crashing error iam getting is</p>
  
  <pre><code>2015-06-09 13:21:31.104 Estater[2170:62264] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[__NSCFArray removeObjectAtIndex:]: mutating method sent to immutable object'
  </code></pre>