Overriding a property in a protocol to make it mutable - objective-c

Question

I'm having some issues trying to override a property in a protocol to make it mutable.
I have this protocol:
#protocol TheProtocol
#property (nonatomic, readonly) NSString *someString;
#end
And this class:
#interface SuperObject : NSObject <TheProtocol>
#end
Which synthesizes the variable like so:
#implementation SuperObject
#synthesize someString;
-(id)init {
if(self=[super init]) {
someString = [aString copy];
}
return self;
}
#end
and can thus write to it internally
I then have a subclass:
#interface SubObject : SuperObject
#end
#implementation SubObject
#synthesize someString;
- (id)init {
if(self=[super init]) {
NSLog(#"Some string is %#",someString");
someString = [bString copy];
}
return self;
}
In my subclass, trying to assign to someString doesn't work. I tried also synthesizing someString in my subclass but before I try and modify it, when I print out "someString", it prints nil instead of "something"
Answered
I figured out the answer. Ultimately what worked is this:
#interface SuperObject : NSObject <TheProtocol> {
#protected
NSString *someString;
}
#end

Answer 1

What is happening is that when you synthesize in your subclass, that is allocating a different ivar than the one in your super class. Therefore the value when printed is nil. You can refer to the original ivar by doing self.someString.
Hope that helps.