Revisit insertFront

Open the LinkedList.java file and find the insertFront method.

public Position<T> insertFront(T data) {
  Node<T> newFront = new Node<T>(data, this);

  Node<T> currFront = head;
  newFront.next = currFront;
  currFront.prev = newFront;
  head = newFront;

  numElements += 1;
  return newFront;
}

The implementation above fails to account for an edge case!

Exercise Identify the edge case and update the implementation.

public Position<T> insertFront(T data) {
  if (head == null) {
    head = new Node<T>(data, this);
    tail = head;
    numElements += 1;
    return head;
  }

  Node<T> newFront = new Node<T>(data, this);

  Node<T> currFront = head;
  newFront.next = currFront;
  currFront.prev = newFront;
  head = newFront;

  numElements += 1;
  return newFront;
}