When should the loadView method be changed?

You should only override the loadView method in cases where you are not using storyboards or .xib files to create the view of the controller (view). In such cases, you create the entire view hierarchy programmatically in loadView, instead of allowing UIViewController to load it from Interface Builder.

Inside loadView, you should:

1. Create a root view (view) for the controller.
2. Assign the created view to the self.view property.

Never call [super loadView] when overriding this method, as it will cause an infinite loop or other undesirable side effects.

// Example of overriding loadView
override func loadView() {
    // Create the root view programmatically
    let newView = UIView()
    newView.backgroundColor = .white

    // Create and add subviews
    let label = UILabel()
    label.text = "Hello from code!"
    label.translatesAutoresizingMaskIntoConstraints = false // Disable Auto Resizing Mask
    newView.addSubview(label)

    // Set up constraints for subviews
    NSLayoutConstraint.activate([
        label.centerXAnchor.constraint(equalTo: newView.centerXAnchor),
        label.centerYAnchor.constraint(equalTo: newView.centerYAnchor)
    ])

    // Assign the created view to the view property of the controller
    self.view = newView
}

Using loadView for programmatic UI creation:

Advantages	Disadvantages
Full control over UI creation.	More code to write.
Ability to create complex, dynamic UI.	Harder to visually assess the UI structure.
Potentially better performance for very complex UI.	Less intuitive for collaborative UI work.

In most modern iOS applications, the preferred approach is to use storyboards or .xib files, where loadView is called automatically to load the view from these resources. Overriding loadView is a lower-level approach that should be used only when truly necessary.