Save NSMutableArray to NSUserDefaults - problems with adding object

Question

I am trying to save an array using NSUserDefaults. I have gotten it to work in other parts of my app and I can't seem to figure out why it doesn't work now. It seems that it is adding (null) to the userDefaults-array, but when I NSLog what I am trying to add ([mainDelegate.globalValdaFragor objectAtIndex:i]) I can see the value I want to input.

The problem seems to be that I can't add anything to the "felPaFragor"-array, seeing as when I try to NSLog it I get (null) and when I tried it with another "random" array it worked.

RPAppDelegate *mainDelegate = (RPAppDelegate *)[[UIApplication sharedApplication]delegate];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

NSMutableArray *felPaFragor = [[NSMutableArray alloc] init];
felPaFragor = [[defaults valueForKey:@"felFragorArray"] mutableCopy];

[felPaFragor addObject:[mainDelegate.globalValdaFragor objectAtIndex:i]];

[defaults setObject:felPaFragor forKey:@"felFragorArray"];

Any help would be greatly appreciated.

Edit: I think I figured it out. It seems I was trying to make a mutableCopy of an empty array and that in turn made my "felPaFragor"-array buggy. Adding this made it work.

felPaFragor = [[NSMutableArray alloc] init];
if ([[defaults valueForKey:@"felFragorArray"] objectAtIndex:0] != NULL) {
    felPaFragor = [[defaults valueForKey:@"felFragorArray"] mutableCopy];
}

It gives (null). Even if I do it directly after adding an object. — Jens Hendar
– Jens Hendar, Commented Jan 14, 2013 at 16:13
Before adding an object, can you insert a NSLog(@"felPaFragor = %@", [felPaFragor description]); and show it's output? — ott--
– ott--, Commented Jan 14, 2013 at 16:15
That gives: felPaFragor = ( ) or if I put if after I add the mutableCopy: felPaFragor = (null) — Jens Hendar
– Jens Hendar, Commented Jan 14, 2013 at 16:16
I think it is giving nil object and it happens when it doesn't found key in the dictionary — Sunil Pandey
– Sunil Pandey, Commented Jan 14, 2013 at 16:25

sergio · Accepted Answer · 2013-01-14 16:27:14Z

1

If after executing this:

NSMutableArray *felPaFragor = [[NSMutableArray alloc] init];
felPaFragor = [[defaults valueForKey:@"felFragorArray"] mutableCopy];

your felPaFragor is nil, then it is highly likely that [defaults valueForKey:@"felFragorArray"] is returning nil.

So, you have a problem with your key, or possibly the object associated to that key has never been stored in NSUserDefaults yet.

answered Jan 14, 2013 at 16:27

sergio

69k11 gold badges105 silver badges123 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Jens Hendar Over a year ago

"or possibly the object associated to that key has never been stored in NSUserDefaults yet." seems to be what was doing it. After adding a check to see if it has been stored before or not it works. Thank you.

meronix · Accepted Answer · 2013-01-14 16:36:07Z

1

first: are you using ARC?

if not, you have a memory leak here:

NSMutableArray *felPaFragor = [[NSMutableArray alloc] init];
felPaFragor = [[defaults valueForKey:@"felFragorArray"] mutableCopy];

the first like create and retain a NSMutableArray never released (and never used: you don't need that line at all, ARC or not ARC)

just use:

NSMutableArray *felPaFragor = [[defaults valueForKey:@"felFragorArray"] mutableCopy];

said that, Sergio's answer may be the right one... your valueForKey:@"felFragorArray" may just never been set when you call it at this point

answered Jan 14, 2013 at 16:36

meronix

6,1661 gold badge25 silver badges36 bronze badges

Collectives™ on Stack Overflow

Save NSMutableArray to NSUserDefaults - problems with adding object

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related