What is the visibility of @synthesized instance variables?

Question

If you have a property in your public interface like the following

@interface MyClass : NSObject
@property(strong) NSString *myProp;
@end

A

Answer 1

A synthesized variable acts as if declared @private:

@interface Garble : NSObject
@property (copy) NSString * s; 
@end
@implementation Garble
@synthesize s;
@end

@interface Bargle : Garble
@end

@implementation Bargle

- (void) useS {
    NSLog(@"%@", s);    // error: instance variable 's' is private
}

@end

I swear I've seen this in the docs, but I can't find it right now. Will update if I track it down.