Should adSubview be placed at the beginning or at the end?

Placing addSubview at the beginning or end depends on the desired view overlay order. Views added later will be positioned above those added earlier.

• At the end (typical case): If the added view should be above existing views in the hierarchy.
• At the beginning: If the added view should be below all or some existing views. You can use insertSubview(_:at:) with index 0 or insertSubview(_:belowSubview:).

// Add above all other views
view.addSubview(newSubview)

// Add below all other views
view.insertSubview(newSubview, at: 0)