Displaying 1st node of a linked list

Question

I was able to get the first value of the linked list but It only works in this scenario. How is it possible to make the getFirst() able to work for any number of values stored in the linked list?

This program outputs: First Number is --> 1

public class LinkedListFirst 
{
 public static void main(String[] args)
   {
      MyLinkedList list = new MyLinkedList();
      list.addFirst(1);
      list.addFirst(2);
      list.addFirst(3);
      list.getFirst();
   }
}

class MyLinkedList
{
private class Node            // inner class
{
  private Node link;
  private int x;
}
//----------------------------------
private Node first = null;    // initial value is null
//----------------------------------
public void addFirst(int d)
{
  Node newNode = new Node(); // create new node
  newNode.x = d;             // init data field in new node
  newNode.link = first;      // new node points to first node
  first = newNode;           // first now points to new node
}
//----------------------------------
 public void getFirst()
 {
   System.out.println( "First Number is --> " + first.link.link.x);
 }
}

I think there may be some confusion of terms. Are you actually after the *last* item in the list? — Jonathan Wilson, Dec 04 '18 at 23:14
@GBlodgett When I do that it just returns the value 3 instead of 1. Do you know why that is? — iSlickBro, Dec 04 '18 at 23:15
@JonathanWilson Since I inserted the value 1 first to the list I want to return that value. — iSlickBro, Dec 04 '18 at 23:18
Why would it return 1? I would run this through the debugger to see what is happening and why — GBlodgett, Dec 04 '18 at 23:18
This question is similar to https://stackoverflow.com/questions/53624675/how-to-find-the-first-value-in-a-linked-list i have written an answer for it here: https://stackoverflow.com/a/53626147/444028 — Abhishek Oza, Dec 05 '18 at 06:35

Jonathan Wilson · Answer 1 · 2018-12-04T23:26:09.880

2

Based on your comments above, I think you're actually after the last item in the list.

Consider this method:

public void getLast()
{
    Node current = first;
    while(current.link != null){
        current = current.link;
    }
    System.out.println("First number is ---> " + current.x);
}

Some of your confusion may arise from the fact that you use the word 'first' too loosely. Yes, you did add the number 1 first, but since you add items to the beginning of the list, it is now the last item of the list.

I hope that helps.

edited Dec 04 '18 at 23:26

answered Dec 04 '18 at 23:22

Jonathan Wilson

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There is a small typo in the print statement :) – mettleap Dec 04 '18 at 23:25
Thanks @mettleap :) – Jonathan Wilson Dec 04 '18 at 23:26

Displaying 1st node of a linked list

1 Answers1