奇怪的iPhone SDK NSUserDefaults行为

Question

I'm experiencing some strange NSUserDefaults behaviour. I save my data, then synchronize, then do a NSlog of the NSUserDefaults to make sure its saved. The data is shown as saved properly from the NSlog, but when I completely close the app (double click home button and kill the app) when it restarts the value has not changed. Whats even stranger is if I repeat the code several times by saving NSUserDefaults, killing the app, reloading the NSUserDefaults sometimes it gets saved properly and other times it does not.

I read this post Strange NSUserDefaults behavior but I am calling synchronize so I don't think thats my problem.

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setObject:@"MyString" forKey:@"testString"];
[[NSUserDefaults standardUserDefaults] synchronize];
NSLog(@"%@", [[NSUserDefaults standardUserDefaults] dictionaryRepresentation]);

Any help is greatly appreciated.

What really confuses me is if the NSLog of standardUserDefaults shows the data is saved why wouldn't it be after the app has been killed???

Thanks

---

UPDATE

---

Looks like the issue was with a mixup in mutable and immutable arrays i was saving to NSUserDefaults. I used mutablecopy when I was retrieving the data and seemed to solve the issue.

Answer 1

For getting the value you could use something like this

NSUserDEfaults *ud = [NSUserDefault standarUserDefaults];
[ud objectForKey=@"YourKey"];

If it returns nil it hasn't been saved.