Question

In Apple’s documentation for their example of a Singleton, and I do understand there’s more than one way to skin a cat — but why do they bother ensuring the instance is registered as static?

Take from: http://developer.apple.com/documentation/Cocoa/Conceptual/CocoaFundamentals/CocoaObjects/chapter_3_section_10.html

I’m referring to:

static MyGizmoClass *sharedGizmoManager = nil;

Answer 1

I believe it is so that the variable can’t be accessed from outside the file for which it is defined. Otherwise it would be globally accessible.

This enforces that a client must use -(id)sharedObject to access the singleton.