I need help coding a doubly linked list from this unfinished code. Everything commented out is what needs to be added. This is done using C# in a Visual Studio Windows Form App. internal class DoubleLinkedList { public DoubleLinkedListNode? firstNode = null; public DoubleLinkedListNode? lastNode = null; public DoubleLinkedListNode? currentNode = null; // other class level variables needed? public DoubleLinkedList() { // creates first node in list with firstValue } public DoubleLinkedList(string firstValue) { // methods and features to add: // get current node reference // insert node before first // delete first node // insert node after last // delete last node // insert node after current - uses multiple methods // delete current // move current to next node // move current to previous node // recursive: find node with value - return reference or null // recursive: get display string } } /******************************* * double Linked List Node - needs to be made generic * class is incomplete * *****************************/ internal class DoubleLinkedListNode { public string? value = null; public DoubleLinkedListNode? nextNode = null; public DoubleLinkedListNode? previousNode = null; public DoubleLinkedListNode(string v) { value = v.ToLower(); } private DoubleLinkedListNode() { value = null; } } .

1. I need help coding a doubly linked list from this unfinished code.
Everything commented out is what needs to be added. This is done using C# in a Visual Studio
Windows Form App.
internal class DoubleLinkedList {
public DoubleLinkedListNode? firstNode = null;
public DoubleLinkedListNode? lastNode = null;
public DoubleLinkedListNode? currentNode = null;
// other class level variables needed?
public DoubleLinkedList() {
// creates first node in list with firstValue
}
public DoubleLinkedList(string firstValue) {
// methods and features to add:
// get current node reference
// insert node before first
// delete first node
// insert node after last
// delete last node
// insert node after current - uses multiple methods
// delete current
// move current to next node
// move current to previous node
// recursive: find node with value - return reference or null
// recursive: get display string
}
}
/*******************************
* double Linked List Node - needs to be made generic
* class is incomplete
* *****************************/
internal class DoubleLinkedListNode {
public string? value = null;
public DoubleLinkedListNode? nextNode = null;
public DoubleLinkedListNode? previousNode = null;
public DoubleLinkedListNode(string v) {
value = v.ToLower();
}
private DoubleLinkedListNode() {
value = null;

2. }
}