What the output should be there?

Question

The output should be

strString = değiştim
wkString  = NULL

but it is not. WHY?

#import <Foundation/Foundation.h>

@interface learnARC : NSObject {
    NSString *strString, __weak *wkString;
}

@property (strong) NSString *strString;
@property (weak) NSString *wkString;

-(void) yaz;

@end

#import "learnARC.h"

@implementation learnARC

@synthesize wkString, strString;

-(void) yaz {
    NSString *anaString = @"anaString";
    strString = anaString;
    wkString = anaString;
    NSLog(@"\nstrString = %@\nwkString  = %@",strString,wkString);

    anaString = @"değiştim";
    NSLog(@"\nstrString = %@\nwkString  = %@",strString,wkString);
}

@end

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        learnARC *lrnarc = [[learnARC alloc]init];
        [lrnarc yaz];
    }
    return 0;
}

Both NSLog statements should genereate the output `"strString = anaString \n nwkString = anastring"` — Hermann Klecker, Apr 12 '13 at 14:32

score 2 · Answer 1 · answered Apr 12 '13 at 14:23

2

WHY?

~~Because you're captalizing your question instead of your class names...~~

Seriously, the weak reference should not be NULL. You have assigned a pointer to it (a pointer to the string @"anaString"). And since string literals have static storage duration, they are never deallocated during the lifetime of the program. (I think you may be confusing variables with properties?)

answered Apr 12 '13 at 14:23

so what is difference between strong and weak for NSString? – agulerer Apr 12 '13 at 14:34
@agulerer Not "for NSString". For every object. The one increases the reference count of the object assigned, the other doesn't. – Apr 12 '13 at 15:15
1

(Which is wholly futile seeing as immutable constant NSStrings have a retain count of close to `NSUIntegerMax`) – CodaFi Apr 12 '13 at 16:01

What the output should be there?

1 Answers1