Updated insert method to allow items to be added to the end of the list.

C#/Program.cs

@@ -29,14 +29,15 @@ list.Append(3);
 list.Append(4);
 list.Append(5);
 list.Append(6);
+list.Insert(6, 1);
 
 Console.Write($"{list[0]} ");
 Console.Write($"{list[1]} ");
 Console.Write($"{list[2]} ");
 Console.Write($"{list[3]} ");
 Console.Write($"{list[4]} ");
-Console.Write($"{list[5]} \n");
-Console.Write($"{list[6]} ");
+Console.Write($"{list[5]} ");
+Console.Write($"{list[6]} \n");
 
 
 //DoublyLinkedList<int> list2 = new DoublyLinkedList<int>();