Swift version: 5.0
UIKit draws views back to front, which means that views higher up the stack are drawn on top of those lower down. If you want to bring a subview to the front, there's a method just for you:
bringSubviewToFront(). Here's an example:
This method can also be used to bring any subview to the front, even if you're not sure where it is:
Available from iOS 2.0
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.