Question

A simple memory management problem as below:

-(void)viewDidLoad
{
    ......
    self.label = [[[UILabel alloc] initWithFrame:labelFrame] autorelease];
    ......
}

I think label is a global variable, according to the management protocol, if you create a instance with “alloc”, you should just “dealloc” it, why “autorelease” here?

Answer 1

self.label = [[[UILabel alloc] initWithFrame:labelFrame] autorelease];

versus

UILabel *temp = [[UILabel alloc] initWithFrame:labelFrame];
self.label = temp;
[temp release];

are essentially the same as far as proper memory management goes. The memory will be properly cleaned up, just at different times.

I would assume that the property of that label would be something like @property(nonatomic,retain) so the label continues to exist since it was retained by the property when you call self.label.