objective-c properties question

Question

I'm new to objective-c and have been wondering what's the point of creating properties? I can just create a variable in the header? Why create a variable and a property with the same name?

Answer 1

Easier memory management (for some), better design (for all). Properties make your public interface to the class concrete, and it defines what is weakly and what is strongly referenced.

Answer 2

As an addition to what Joshua have said: properties are KVC/KVO-compatible while variables are not, whole Cocoa stands on KVO. You can bind a property and to property, you can add an observer, you can use valueForKey/valueForKeyPath and their 'set' brothers for free. If the value must be published (i.e. available for external classes) - make a property, you will get a lot of stuff for free. Just make sure you've set the proper memory management option (assign, copy or retain) and thread-safety modifier (nonatomic).