iPhone Super/SubClass Example - objective-c

Question

I have a superclass Question:
import <Foundation/Foundation.h>
#import "Answer.h"
#interface Question : NSObject {
NSString* qId;
NSString* qTitle;
NSString* qNumber;
NSString* sectionId;
NSString* type;
Answer* answer;
}
#property (nonatomic, retain) NSString* qId;
#property (nonatomic, retain) NSString* qTitle;
#property (nonatomic, retain) NSString* qNumber;
#property (nonatomic, retain) NSString* sectionId;
#property (nonatomic, retain) NSString* type;
#property (nonatomic, retain) Answer* answer;
#end
#import "Question.h"
#implementation Question
#synthesize qId, qTitle, qNumber, sectionId, type, answer;
-(id)init
{
if (self = [super init])
{
// Initialization code here
answer = [[Answer alloc]init];
}
return self;
}
-(void) dealloc{
[answer release];
[super dealloc];
}
#end
I have several types of Question, one example is a Slider Question. I want this class to subclass Question:
#import <Foundation/Foundation.h>
#import "Question.h"
#interface SliderQuestion : Question {
(NSString*) min;
(NSString*) max;
}
#property (nonatomic, retain) NSString* min;
#property (nonatomic, retain) NSString* max;
#end
}
#import "SliderQuestion.h"
#implementation SliderQuestion
#synthesize min, max;
#end
Is this the correct way to subclass? Will SliderQuestion inherit the properties contained within Question?
SliderQuestion* s = [[SliderQuestion alloc]init];
NSLog(#"%#", s.qId); //is this valid

Answer 1

Do you really want min and max to be instances of NSString? It seems that floats would be more appropriate.
Also, scrap the () in (NSString *) to remove the warning/error message.
Finally, this is the appropriate way to subclass. An instance of SliderQuestion will inherit all properties and methods of the Question class (and NSObject as well)

Answer 2

Notice the ( and ) around the NSStrings, you might wanna remove those.