I don't fully understand sendSubviewToBack. Please, see the code

Question

You can see my screenshot of xib's file.

I do some manipulation in viewDidLoad

-(void) viewDidLoad
{
 [smallView removeFromSuperview];
 [bigView sendSubviewToBack:smallView];
}

Will the hierarchy change from view->bigView->smallView to view->smallView->bigView?

Answer 1

No the hierarchy will not be affected. The documentation says:

sendSubviewToBack:
Moves the specified subview so that it appears behind its siblings.

It changes the order of painting subviews. If you have two views which are overlapping and have the same superview then you will be able to define which of that two views should be in front.