What is superview and what is subviews?
When I add this code:
[self.view addSubview:self.frontView];
// what does that mean ?
And...
@property (nonatomic, strong) IBOutlet UIImageView *frontView;
[self.frontView superview] != nil // means ?
what is in superview?
A superview is a view that holds other views over it and subviews are the views being held/added over a View.
Let's assume we have a view named MyView, which holds a UIButton (named loginButton) over it. Here MyView is considered a superview for loginButton and loginButton is considered a subview of MyView.
For more, you should start from here
As per the provided code snippet.
[self.view addSubview:self.frontView];
Hence view (Controller's view) is a superview and frontView is a subview
"superview" means the view which holds the current one. "subviews" means the views which are holding by the curent view.
For example, you have a view (will call it as MyView) which include a button. Button is a view too (UIButton is a kind of view). So, MyView is superview for the button. Button is a subview for MyView.
See Apple's View Programming Guide, section View Hierarchies and Subview Management
subview is childview ( which is added on any view)
superview is parentview (on which subview is added)
