Remove the node that contains the key from the Linked list

Question

I have a remove method , find the element in that list and delete it.That topic is about Doubly linked list.Is my operation true in if and else if statement for the formation of the new list?

public void Remove(int key) {//key = number in the list.
        if (head == null) {
            System.out.println("Empty List..!");
        } else if (key == head.key) {
            head.prev.next = head.next;
            head.next = null;
            noOfNodes--;
        } else if (key == tail.key) {
            tail.next.prev = tail.prev;
            tail.prev = null;
            noOfNodes--;
        } else {
            for (LinkedListNode temp = head; temp.next != null; temp = temp.next) {
                if (temp.key == key) {
                    temp.prev.next = temp.next;
                    temp.next.prev = temp.prev;
                    temp.prev = null;
                    temp.next = null;
                    noOfNodes--;
                }
            }
        }
    }

Possible duplicate of [What is a Null Pointer Exception, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-null-pointer-exception-and-how-do-i-fix-it) — Seelenvirtuose, Nov 18 '15 at 20:23
This might be the issue `tail.next.prev = tail.prev;`. Are you sure `tail.next` is not null? Isn't `tail` the last element of your doubly linked list? — Atri, Nov 18 '15 at 20:32
@ashutosh You are absolutely right. Thanks for your comment. I corrected my code thanks to you. — ZpCikTi, Nov 19 '15 at 14:02

score 0 · Accepted Answer · answered Nov 19 '15 at 14:21

0

From your code, it looks like tail is the last node of your linked list.

So, this might be the issue tail.next.prev = tail.prev;. Since tail.next is null as tail is the last element, when you access prev on tail.next it throws NullPointerException.

answered Nov 19 '15 at 14:21

Atri

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Remove the node that contains the key from the Linked list

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