Question

In my setter I have a incoming string that I am copying to avoid any trouble should the original be modified.

- (void)setName:(NSString *)newName{
    if(name != newName) {
        [name release];
        name = [newName copy];
    }
}

My question is: as I am doing a copy where should I release it, or do I just do an autorelease? i.e.

- (void)setName:(NSString *)newName{
    if(name != newName) {
        [name release];
        name = [[newName copy] autorelease];
    }
}

gary

Answer 1

In my setter I have a incoming string that I am copying to avoid any trouble should the original be modified.

- (void)setName:(NSString *)newName{
  if(name != newName) {
      [name release];
      name = [newName copy];
  }
}

My question is: as I am doing a copy where should I release it, or do I just do an autorelease? i.e.

- (void)setName:(NSString *)newName{
  if(name != newName) {
      [name release];
      name = [[newName copy] autorelease];
  }
}

As I said on your other question, autorelease translates to “send yourself release later”. That means that it counts as a release.

So, your second example releases the old value of name (good), then makes a copy of the new one (good), then puts the new one in line to be released (bad), then puts this now-doomed object into the instance variable (really bad).

The first example is correct, because you still hold a retention on the object after you put it in the instance variable.

As I also said on your other question, I think you should review the memory-management rules.