Which of the following statements regarding Objective-C are correct?

Which need to be modified while localizing an application?

Which symbol is used as a syntactic marker for blocks of code in iPhone OS 4.0?

What will you get from the default database? NSUserDefaults *defs = [NSUserDefaults standardUserDefaults]; NSArray *languages = [defs objectForKey:@'AppleLanguages']; NSString *preferredLang = [languages objectAtIndex:0];

What is the data type of extendStart parameter of function CGShadingCreateAxial of class CGShading?

The genstrings tool can parse _____.

What does the 'strong' property attribute do?

What is true about ARC and manual memory management?

Which allows it to determine if an application is running on iPhone, or if it's running on an iPod Touch?

Consider the following code: (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { // Set Background Color/Pattern self.window.backgroundColor = [UIColor blackColor]; self.tabBarController.tabBar.backgroundColor = [UIColor clearColor]; //self.window.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@'testbg.png']]; // Set StatusBar Color [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackTranslucent]; // Add the tab bar controller's current view as a subview of the window self.window.rootViewController = self.tabBarController; [self.window makeKeyAndVisible]; return YES; } How can the error be corrected that gets thrown in the console, 'Applications are expected to have a root view controller at the end of application launch'?

Is OpenAL available on the iPhone?