Question

I’m basically trying to add a new string to my NSMutableArray using this code in ViewWillAppear

    NSUserDefaults *favBooksDefaults = [NSUserDefaults standardUserDefaults];
    self.favBook = [favBooksDefaults stringForKey:@"favBook"];
    self.favBookList = [[NSMutableArray alloc]init];
    [self.favBookList addObject:favBook];

Of course, while I do this, I want to preserve ALL the previous strings that were present in the Array. Because when I add a new string for the NSUserDefaults and then to the Array, it simply substitutes the old one.

Why is that and how can I save all the objects?
Thanks in advance.

Answer 1

Mr Br.’s answer is correct:

In your header file declare favBookList as a property and include a book adding method:

@interface yourViewController : UIViewController {
NSMutableArray *favBookList;
}

-(void)addBook;

@property (nonatomic, retain) NSMutableArray *favBookList;

In your viewDidLoad method, initialize favBookList. Don’t forget @synthesize!

-(void)viewDidLoad {
self.favBookList = [[NSMutableArray alloc] init];
[super viewDidLoad];
}

Now you are free to add a book from your user defaults at any time.

-(void)addBook{
self.favBook = [[NSUserDefaults standardUserDefaults] stringForKey:@"favBook"];
[favBookList addObject:favBook]; 
}