Question

I have just been looking at some old code and it got me thinking about which of these to use, both seem to work without complaint. I was just curious when I spotted the difference.

THIS:

id <UIApplicationDelegate> appDelegate = [[UIApplication sharedApplication] delegate];

OR

id appDelegate = [[UIApplication sharedApplication] delegate];

Answer 1

i guess it depends on what you are asking to appDelegate

i mean, if you are going use the property “window” which is defined in UIApplicationDelegate protocol:

NSLog(@"%@",  appDelegate.window);

then you should use :

id <UIApplicationDelegate> appDelegate = [[UIApplication sharedApplication] delegate];

but if you try:

id appDelegate = [[UIApplication sharedApplication] delegate];
NSLog(@"%@",  appDelegate.window);

you’ll get an error…