How do I create a node from a class? - c++

Question

Trying to finish my doublely linked list program, but I don't really know how to create a node using a class. I've only ever used sctructs.
DoubleNode.h:
#ifndef DOUBLE_NODE_H_
#define DOUBLE_NODE_H_
template<class ItemType>
class DoubleNode
{
private:
ItemType item;
DoubleNode<ItemType>* prev;
DoubleNode<ItemType>* next;
public:
DoubleNode(const ItemType& anItem, DoubleNode<ItemType>* prevPtr, DoubleNode<ItemType>* nextPtr);
~DoubleNode();
ItemType getItem() const;
DoubleNode<ItemType>* getPrev() const;
DoubleNode<ItemType>* getNext() const;
void setPrev(DoubleNode<ItemType>* prevPtr);
void setNext(DoubleNode<ItemType>* nextPtr);
};
#endif
DoubleNode.cpp:
#include "DoubleNode.h"
template<class ItemType>
DoubleNode<ItemType>::DoubleNode(const ItemType& anItem, DoubleNode<ItemType>* prevPtr, DoubleNode<ItemType>* nextPtr) :
item(anItem), prev(prevPtr), next(nextPtr)
{
}
template<class ItemType>
DoubleNode<ItemType>::~DoubleNode()
{
this->prev = this->next = nullptr;
}
template<class ItemType>
ItemType DoubleNode<ItemType>::getItem() const
{
return this->item;
}
template<class ItemType>
DoubleNode<ItemType>* DoubleNode<ItemType>::getPrev() const
{
return this->prev;
}
template<class ItemType>
DoubleNode<ItemType>* DoubleNode<ItemType>::getNext() const
{
return this->next;
}
template<class ItemType>
void DoubleNode<ItemType>::setPrev(DoubleNode<ItemType>* prevPtr)
{
this->prev = prevPtr;
}
template<class ItemType>
void DoubleNode<ItemType>::setNext(DoubleNode<ItemType>* nextPtr)
{
this->next = nextPtr;
}
These two files were provided by my professor, and I need to implement another class called DoubleListInterface.h. I'm working on that right now, but I don't really know if I've even created the nodes right.
Here's my DoubleList.cpp insertFront implementation so far:
template<class ItemType>
bool DoubleList<ItemType>::insertFront(const ItemType& newEntry)
{
DoubleNode<ItemType>* n; // Creating pointer to node
DoubleNode<ItemType>* head;
DoubleNode<ItemType>* tail;
// If list is empty, this is the first node
if (itemCount == 0){
n = new DoubleNode<ItemType>; // Creating node
n->this->item(newEntry); // Putting item in node
n->prev = NULL; // First node, so prev is null
head = n; // Both head and tail would be at this node
tail = n;
itemCount++; // Increment itemCount
}
else{
DoubleNode<ItemType>* temp = new node; // Creating a filling new node
temp->this->item(newEntry);
temp->this->setPrev(head->this->getPrev()); // Set prev to the prev of head pointer
temp->this->getNext() = this->head; // Make next point to the head
head->this->getPrev() = temp; // Point prev of the old head node to the newly created node
head = temp; // Temp is the new head
delete temp; // Delete temp pointer
temp = NULL;
itemCount++; // Increment intemCount
}
return true;
}
I get a lot of errors when I run this, the majority of which are "expected unqualified-id before 'this'" on every place that I use a this pointer. Don't really know what that means either, but I'd really like to know if I'm creating the nodes right. Thanks for anything you can contribute.

Answer 1

You can't point to this.
For example, you wrote
temp->this->item(newEntry);
The correct way to do this is
temp->item(newEntry);