Question

All the tutorials I have done say that I set stuff to nil in viewDidUnload and then release in dealloc. However I am being told that this would cause a memory leak since viewDidUnload gets called before a dealloc and so I am unable to release anything that is set to nil.

Can someone help clarify?

Answer 1

If you create an object (with alloc and init) in viewDidLoad, then you should release it in viewDidUnload. The reason is that sometimes viewDidUnload is called to save memory, but dealloc is not called. Then, later, viewDidLoad may be called again. In general, release anything you allocate in the inverse method, e.g.

If you allocate an object in init, then release it in dealloc.

If you allocate an object in viewDidLoad, then release it in viewDidUnload.

If you allocate an object in viewWillAppear (or viewDidAppear), then release it in viewWillDisappear (or viewDidDisppear).