adding objects crash in ios

Question

i am trying to add an object into a nsuserdefault, but i get this crash "[__NSCFArray insertObject:atIndex:]: mutating method sent to immutable object" its crashing on this line: [currentFav addObject:incomingBabe];

I have no idea why its crashing, its working on my other project.

here is my code

-(IBAction)favorite {
    NSUserDefaults *standardDefault = [NSUserDefaults standardUserDefaults]; 
    NSMutableArray *currentFav = [[NSUserDefaults standardUserDefaults]objectForKey:@"fav"];
    NSLog(@"strings stored = %@",currentFav);
    NSMutableArray *newFav = [NSMutableArray arrayWithObject:[NSString stringWithFormat:@"bikini%02d.jpeg",self.currentNumber]];

if (currentFav == NULL){
   currentFav = [[NSMutableArray alloc]init];
  }
  for(NSString *incomingBabe in newFav){
  BOOL hasStringAlready = NO;
  for(NSString *currentFavorite in currentFav){
  if([currentFavorite isEqualToString:incomingBabe]){
    hasStringAlready = YES;
    NSLog(@"has string already");
    break;
    }
  }
if (!hasStringAlready) {
  [currentFav addObject:incomingBabe];
  hasStringAlready = YES;
  }
}

 [standardDefault setObject:currentFav forKey:@"fav"];
 [standardDefault synchronize];
}

Michael Francis · Accepted Answer · 2012-08-02 00:35:51Z

2

Basically it says you are trying to use a method from NSMutableArray on NSArray.

This is because "Values returned from NSUserDefaults are immutable, even if you set a mutable object as the value."

NSMutableArray *currentFav = [[NSUserDefaults standardUserDefaults]objectForKey:@"fav"];

will return an array, not mutable array. You should make a mutable copy of it.

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

edited Aug 2, 2012 at 0:35

Michael Francis

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answered Aug 2, 2012 at 0:21

Selkie

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Comments

Siam · Accepted Answer · 2012-08-02 02:38:50Z

0

You can get the reason of your problem from 1 floor. You can use his method to solve your problem, or like this:

NSMutableArray *currentFav = [NSMutableArray arrayWithArray:[[NSUserDefaults standardUserDefaults]objectForKey:@"fav"]];

answered Aug 2, 2012 at 2:38

Siam

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