iOS View controller memory management
![iOS View controller memory management](https://res.cloudinary.com/audiodog/image/upload/w_640,h_155,c_scale,f_auto,q_auto/v1513806711/images/site/blog_banner_light.png)
Memory management key:
viewDidUnload is only called if there is a low memory situation and your view is not the active view.
otherwise just calls dealloc.
For all view controllers simulate memory warning to test their handling
viewDidLoad v viewWillAppear: viewWillAppear is called multiple times, everytime the view comes back into view. For example
when a modal view is quit revealing the original view again.