Doubly linked lists?

[Dkob1]

I think all of these are the characteristics but please let me know if any are not.

What are the characteristics of doubly linked list's sentinels, header and trailer?

-The header and trailer sentinels mark the ends of the doubly linked list.

-The header sentinel's next pointer points to the first data node of the non-empty list.

-The trailer sentinel's next pointer points to the last data node of the non-empty list.

-In an empty list, the header sentinel's next pointer points to the trailer sentinel, and the trailer's prev pointer points to the header sentinel.

-The header sentinel's previous pointer and trailer sentinel's next pointer can be set to null.

[keskiverto]

Do you mean that you have something like:

struct Node {
  Node * prev = nullptr;
  Node * next = nullptr;
  ValueType data;
};

class List {
  Node header;
  Node trailer;
};

What would happen if you had:

class List {
  Node * header = nullptr;
  Node * trailer = nullptr;
};

[Dkob1]

I think so, that was just the question.