Question

In Apple’s The Objective-C Programming Language p. 18, they make a distinction between setting a variable with self versus instance reference. e.g
myInstance.value =10;
self.value =10;
1. Would these two set different properties named value?
2. How could self work if there are several instances with properties named value?
They also assert, “If you do not use self., you access the instance variable directly.” This would mean that the accessor would not be called if you use
myInstance.value =10;
and KVO wouldn’t work. Is this true?
3. Using @Property and @Synthesize (with garbage collection), what is the proper way to set properties of different instances? And what good is the self reference?
A numeric example would help me, please.

Answer 1

My big problem was how an ivar and a property could be tied together when they have different names, especially with multiple ivars.
I finally found that if name of property doesn’t match name of ivar, a new ivar is synthesized. This is accessed by self.propertyname (within object) or object.propertyname (outside of object), not the declared ivar.

To tie disparate names of ivar and property, equate them as in
@synthesize propertyname = ivarname.

Thanks to

http://blog.ablepear.com/2010/05/objective-c-tuesdays-synthesizing.html