 Solution

ID: past-exam-of-the-year-1-of-the-computer-science-course-of-the-university-of-oxford/2019/imperative-programming-resit/3/b/solution

The linked list node needs mutable fields for changing a stored number and rearranging links:

class Node(var name: String, var number: String, var next: Node)

The implementation will keep its real linked list nodes private to the Book object and will not return linked list node references to clients.

 New to topics? Read the docs here!