editButtonItem
Returns a bar button item that toggles its title and associated state between Edit and Done.
Declaration
var editButtonItem: UIBarButtonItem { get }Discussion
If one of the custom views of the navigationItem property is set to the returned object, the associated navigation bar displays an Edit button if isEditing is false and a Done button if isEditing is true. The default button action invokes the setEditing(_:animated:) method.