CODEWITHSUNDEEP
iphoneobjective-cios
onkar
onkar

Reputation: 51

How do I access the value of variable

In my .h file

@interface DemoApp : UIViewController   {
    UITextView *textView;
@private

    NSString *status;

    NSInteger *track1Len,*track2Len;


}
@property (nonatomic,retain) NSString *status;

In .m file 

    @synthesize status;
- (void)onDecodeCompleted:(NSString *)sts
{
   status=sts;
   NSLog(@"status is %@",status);

}

- (IBAction)processButton:(id)sender
{
   NSLog(@"status is %@",status);
   // here I am getting null value
}

I just to access my variable throughout my class file.In ondecodecompleted method,I am getting the value that is passed as parameter but after the process button is pressed I am getting null value.

Upvotes: 0

Views: 58

Answers (2)

Vincent Bernier
Vincent Bernier

Reputation: 8664

The Reason why you are losing your iVar is because you are not getting ownership on your variable when you are setting it directly.
You need to do status = [sts copy]; OR status = [sts retain] to take ownership.
If you don't take ownership status will have the life span of stswhich is probably not what you want.

Accessing iVar directly is usually a bad idea because of the local memory management that you need to remember to do right each time.
The best practice is to use your @property with dot syntax. the property will take care of the memory management of setters accordingly to the one you will have declared.

Upvotes: 0

Alan
Alan

Reputation: 46813

try: self.status in both places.

- (void)onDecodeCompleted:(NSString *)sts
{
   self.status=sts;
   NSLog(@"status is %@",self.status);

}

- (IBAction)processButton:(id)sender
{
   NSLog(@"status is %@",self.status);
   // here I am getting null value
}

Also since you are using NSString which has a mutable subclass, you should mark it as copy and not retain

@property (nonatomic,copy) NSString *status;

Upvotes: 2

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