apradanas

If you are dealing with an unstable API, you may want to iterate through all the keys to check for null. This will prevent crash when saving the object as well.

+ (id)replaceNullWithEmptyStringForObject:(id)object {
    if ([object isKindOfClass:[NSArray class]]) {
        NSMutableArray *mutableArray = [object mutableCopy];
        [mutableArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            [mutableArray setObject:[self replaceNullWithEmptyStringForObject:obj] atIndexedSubscript:idx];
        }];