A view controller manages a single root view, which may itself contain any number of subviews . User interactions with that view hierarchy are handled by your view controller, which coordinates with other objects of your app as needed. Every app has at least one view controller whose content fills the main window.
Read moreHow do I show view in Xcode?
Click on the left-most view (i.e. the one in the very back) and you’ll see that Xcode highlights it to indicate your selection. You’ll also see the Jump Bar (just above the Canvas) update to show a UIWindow as the last item — that last item will always reflect the currently selected view and its class type.
Read moreHow do I change the default view controller in Xcode?
Changing the Initial View Controller in Xcode
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