iphone programming + memory leak - iphone

Question

I am getting memory leak theFileName = [[responseString lastPathComponent]stringByDeletingPathExtension];
theFileName is a global variable. I have synthesized it and
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]))
{
// Custom initialization
theFileName = [[NSString alloc] init];
}
return self;
}
- (void)requestFinished:(ASIHTTPRequest *)request{
//internally calls this function
// Use when fetching text data
NSString *responseString = [request responseString];
//NSLog(#"the responsestring for download is:%#",responseString);
theFileName = [[responseString lastPathComponent]stringByDeletingPathExtension];
//NSLog(#"the theFileName for download is:%#",theFileName);
//adds extension .jpg to file name
NSString *jpg=#".jpg";
NSString *addjpg=[theFileName stringByAppendingString:jpg];
//NSLog(#"append %#",addjpg);
}
Released it in dealloc.
-(void)dealloc
{
[thefileName release];
}
}

Answer 1

theFileName = [[responseString lastPathComponent]stringByDeletingPathExtension];
creates a new object for theFileName, which already holds an NSString object. You need to release that old value before, i.e.
[theFileName release];
theFileName = [[responseString lastPathComponent]stringByDeletingPathExtension];
You might consider using a copy (recommended) or retain property for theFilename, and use the dot-syntax in requestFinished:.

Answer 2

Here are a few things that might help.
You're not calling super's dealloc method within self's dealloc. For example,
- (void) dealloc
{
[self.theFileName release];
[super dealloc];
}
You're not using the getters and setters that come with synthesizing a property, and we don't know what property you've used with theFileName. If you've got a retaining property, i.e. a statement like #property (copy) NSString * theFileName then you should use the setter so that you don't trip up on retain counts. For example,
(id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]))
{
// Custom initialization
NSString * aFileName = [[NSString alloc] init];
[self setTheFileName:aFileName];
[aFileName release];
}
return self;
}
is better.