Question

I have a weird problem.
pictureLink is a global variable declared in .h

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

i wrote this code

NSString * myPictureUrl=[NSString stringWithFormat:@"http://mywebsite.com/uploads/%@.jpg",hash];
pictureLink=myPictureUrl;

I have a strange result, it must be a pointer
Or

pictureLink=[NSString stringWithFormat:@"http://mywebsite.com/uploads/%@.jpg",hash];

i have EXC_BAD_ACESS error

Answer 1

It’s memory management fault, you’re not retaining myPictureUrl in your code.

[NSString stringWithFormat:@"http://mywebsite.com/uploads/%@.jpg",hash]; returns an autoreleased value, so you have two options:

1. pictureLink=myPictureUrl; should look like [self setPictureLink:myPictureUrl];.
2. do a [myPictureUrl retain];, and don’t forget to release it later.

Consider using ARC (Automatic Retain Counting) for you project. With ARC the compiler takes care of retain counts so you don’t have to, in fact aren’t allowed to. There is a refactoring that will convert a current project.