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Thread: Java Code Error - Reversing a Linked List

  1. April 28th, 2023, 01:55 AM #1
    Vithika Dutt
    Vithika Dutt is offline
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    Default Java Code Error - Reversing a Linked List

    Hello,

    I'm having an issue with a piece of code I'm writing in Java to reverse a linked list: https://www.interviewbit.com/blog/re...a-linked-list/. I've been trying to debug it for a few hours but I'm still having issues. The code is as follows: 
    public void reverseLinkedList(Node head) { 
    Node current, next, prev; 
    current = head; 
    prev = null; 
 
    while (current != null) { 
        next = current.next; 
        current.next = prev; 
        prev = current; 
        current = next; 
    } 
    head = prev; 
}
    The error I'm getting is "Error: null pointer exception." I'm not sure why this is happening and would appreciate any help I can get.

    Thanks in advance!
    Last edited by Norm; April 28th, 2023 at 01:09 PM. Reason: Added code tags
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