how to clear all NSUserDefaults values in objective-C?

Question

I am using NSUserDefaults lots of time in my app to store some values, but on "refresh button" i want to clear all stored values, Is there any way to clear all NSUserDefaults values?

Answer 1

You can remove all stored value using below code see here for more details

- (void)removeUserDefaults 
{
    NSUserDefaults * userDefaults = [NSUserDefaults standardUserDefaults];
    NSDictionary * dict = [userDefaults dictionaryRepresentation];
    for (id key in dict) {
        [userDefaults removeObjectForKey:key];
    }
    [userDefaults synchronize];
}

Or in shortest way

[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];

Swift

let defaults = UserDefaults.standard
defaults.dictionaryRepresentation().keys.forEach { (key) in
    defaults.removeObject(forKey: key)
}

Answer 2

You can clear your user defaults by using following statements -

NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];

You can call a selector on the refresh button and keep the above statements in it, as-

- (void) refreshUserDefaults
{
    NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
    [[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];
}