mutating method sent to immutable object

Question

When I use this method first time it works fine, but when I called it second time I get the error \"mutating method sent to immutable object\". The problem is at line with \"add

Answer 1

placesT is a non mutable array, either always set placesT a mutable object always or use following code.

NSMutableArray *placesT= [[[NSUserDefaults standardUserDefaults] objectForKey:@"placesT"] mutableCopy];