What methods are used to display and update the user interface in UIKit?

In UIKit, the following methods are used to display and update the user interface:

• setNeedsDisplay() — marks the view as needing to be redrawn. The system will call the draw(_:) method in the next update cycle.

• setNeedsLayout() — marks the view as needing layout update. After this, layoutSubviews() will be called.

• layoutIfNeeded() — forces the view to immediately perform layout if it has been marked as necessary.

Example of updating the interface:

myView.setNeedsLayout() // mark for layout update
myView.layoutIfNeeded() // perform update immediately

To update content (for example, text in UILabel), it is enough to change the property, and UIKit will automatically update the display.