I am having trouble with printing out the number to the console. Instead of 10 printing out I want 16. How can this be fix.

using System;
using System.Collections.Generic;
using System.Text;

namespace LinkList
{
    class Program
    {
        static void Main(string[] args)
        {
            List studentRecord = new List();
            studentRecord.InsertAtFront(10);
            studentRecord.InsertAtFront(16);
            studentRecord.InsertAtBack(32);

            studentRecord.PrintFromLeftToRight();
        }
    }

    public class ListNode
    {
        private object data;
        private ListNode next;
        private ListNode prev;

        public ListNode(object dataValue, ListNode n, ListNode p)
        {
            data = dataValue;
            next = n;
            prev = p;
        } // end constructor

        public ListNode Next
        {
            get { return next; }
            set { next = value; }
        } // end property Next

        public ListNode Prev
        {
            get { return prev; }
            set { next = value; }
        } // end property Prev

        public object Data
        {
            get { return data; }
            set { data = value; }
        } // end property Data
    } // end class ListNode

    public class List
    {
        private ListNode firstNode;
        private ListNode lastNode;
        ListNode temporary;

        public List()
        {
            firstNode = lastNode = null;
        } // end constructor List

        public ListNode FirstNode
        {
            get { return firstNode; }
            set { firstNode = value; }
        }

        public ListNode LastNode
        {
            get { return LastNode; }
            set { LastNode = value; }
        }

        public void InsertAtFront(object insertItem)
        {
            if (firstNode == null)     // link list is empty
                firstNode = lastNode = new ListNode(insertItem, null, null);
            else
                firstNode = new ListNode(insertItem, firstNode, null);
        } // end method InsertAtFront

        public void InsertAtBack(object insertItem)
        {
            if (firstNode == null)
                firstNode = lastNode = new ListNode(insertItem, null, null);
            else
                firstNode = new ListNode(insertItem, null, lastNode);
        } // end method InsertAtBack

        public void PrintFromLeftToRight()
        {
            if (firstNode == null)
            {
                Console.WriteLine("Link List is empty.");
                return;
            } // end if
            else
            {
                ListNode currentNode = lastNode;
                Console.WriteLine("{0,4}", currentNode.Data);
            } // end else
        } // end method PrintFromLeftToRight
    } // end class List
}

I found an error I think you should fix. Last line in InsertAtBack, shouldn't you be modifying lastNode and not firstNode? After that the linked-list works as it should, except it will print 32 when you call printfromlefttoright. That is because in that method you told it to print lastNode.

HTH

Also there doesn't seem to be any funcionality in your linkedlist that isn't present already in the linkedlists the .NET framework has to offer. Unless you're doing it juts purely for a learning experience.

His list supports mixed data types

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