Apple

Am 07.11.2008 um 13:17 schrieb Roland King:

On Nov 7, 2008, at 7:59 PM, Calum Robertson wrote:
Below is a snippet of code from the "Creating an iPhone Application" document from the iPhone DevCenter.
- (void)applicationDidFinishLaunching:(UIApplication *)application
{
  // Set up the view controller
  UIViewController *aViewController = [[UIViewController alloc]
             initWithNibName:@"MoveMeView" bundle:[NSBundle mainBundle]];
  self.viewController = aViewController;
  [aViewController release];

...
}

In this case whatever self is has declared viewController as a readwrite/retain property, so self.viewController = aViewController is the same as [ self setViewController:aViewController ] and perhaps you're happier with that syntax and realizing that the implementation of setViewController would retain the object and the dealloc() will eventually release it.

Lets forget for a moment that the dealloc never get's called at all on the iPhone - when you press the home button the app just quits and iPhoneOS throws away all alloc'ed memory at once instead of letting the app do it one by one which would last longer with the same result - but anyway, what's the reason for defining a local variable aViewController to receive the UIViewController pointer, then copying that to the instance variable with a setter method which increases the retain count, then decrease the retain count again - instead of just using the instance variable?

viewController = [[UIViewController alloc]
initWithNibName:@"MoveMeView" bundle:[NSBundle mainBundle]];

since "viewController" is a member of the class, you don't need the "self.".

So why the local var?

3 lines of code instead of 1...

Isn't a main goal of Cocoa to write *less* code?