NSUserDefaults category not saving in didFinishLaunchingWithOptions()

Question

I have made a category for saving number of app runs like so,

static NSString * const AppRuns = @"IP_AppRuns";

@implementation NSUserDefaults (RegisteredUser)

+ (void)saveRuns:(NSNumber *)value
{
    [[NSUserDefaults standardUserDefaults] setObject:value forKey:AppRuns];
}

+ (NSNumber *)runs
{
    return [[NSUserDefaults standardUserDefaults] objectForKey:AppRuns];
}
....

And I'm setting it in my App delegate didFinishLaunchingWithOptions method.

[NSUserDefaults saveRuns: @(21)];
[[NSUserDefaults standardUserDefaults] synchronize];
NSLog(@"App has run %ld times", [[NSUserDefaults runs] integerValue]);

But, I get EXC_BAD_ACCESS, which makes me suspect that it isn't getting saved.

However, the following works:

[[NSUserDefaults standardUserDefaults] setObject:@(17) forKey:@"AppRuns"];
[[NSUserDefaults standardUserDefaults] synchronize];
NSLog(@"App has run %ld times", [[[NSUserDefaults standardUserDefaults] valueForKey:@"AppRuns"] integerValue]);

What am I doing wrong?

Answer 1

+ (NSNumber *)runs uses objectForKey to access NSUserDefaults

Your second example uses valueForKey to access NSUserDefaults

valueForKey and objectForKey both will return the object for the given key. But here valuForKey is key-value coding (KVC).

If key does not start with “@”, invokes objectForKey: . If key does start with “@”, strips the “@” and invokes [super valueForKey:] with the rest of the key.

EDITED

Can you reinstall your app(clean old NSUserDefaults values) and try this code?

@implementation NSUserDefaults (RegisteredUser)

+ (void)saveRuns:
{
    NSNumber *runs = [[NSUserDefaults standardUserDefaults] objectForKey:AppRuns];
    [[NSUserDefaults standardUserDefaults] setObject:runs++ forKey:@"Runs"];
    [[NSUserDefaults standardUserDefaults] synchronize];
}

+ (NSNumber *)runs
{
    return [[NSUserDefaults standardUserDefaults] objectForKey:@"Runs"];
}