Circularly linked queue not enqueing values - c++

Question

I have to implement a Circularly linked queue class as the LinkedQueueType class. For some reason, when I call the enqueue function, it isn't getting added to the queue, even my test prints don't print out. Here is my queue class:
#define LINKED_QUEUE_H
class FullQueue {};
class EmptyQueue{};
typedef int ItemType;
struct NodeType{
ItemType info;
NodeType* next;
};
class LinkedQueueType {
public:
LinkedQueueType ();
// Class constructor.
// Because there is a default constructor, the precondition // that the queue has been initialized is omitted. LinkedQueueType(const LinkedQueueType& qt);
//Copy Constructor
LinkedQueueType operator=(const LinkedQueueType& rhs); //Overloaded assignment operator=
~LinkedQueueType ();
// Class destructor.
void MakeEmpty();
// Function: Initializes the queue to an empty state.
// Post: Queue is empty.
bool IsEmpty() const;
// Function: Determines whether the queue is empty.
// Post: Function value = (queue is empty)
bool IsFull() const;
// Function: Determines whether the queue is full. // Post: Function value = (queue is full)
void Enqueue(ItemType newItem);
// Function: Adds newItem to the rear of the queue. // Post: newItem is at rear of queue.
void Dequeue(ItemType& item);
// Function: Removes front item from the queue and returns it in // item.
// Post: If (queue is empty) EmptyQueue exception is thrown
// and item is undefined
// else front element has been removed from queue and
// item is a copy of removed element.
void Print(); //Print function
private:
NodeType* rear;
int length;
};
#endif
and here is the implementation for the enqueue function:
void LinkedQueueType::Enqueue(ItemType newItem){
NodeType *newNode=nullptr;
NodeType*temp=nullptr;
newNode->info=newItem;
newNode->next=nullptr;
if(rear==nullptr){
rear=newNode;
}else{
temp=rear->next;
rear->next=newNode;
}
rear=newNode;
rear->next=temp;
}
Here is my testing:
cout<<"hi";
LinkedQueueType q;
q.Enqueue(5);
When I run my driver, it doesn't print, could someone show me the way!

Answer 1

This is your code:
NodeType *newNode=nullptr;
NodeType*temp=nullptr;
newNode->info=newItem;
newNode->next=nullptr;
This is what you are saying:
Make a new pointer called newNode of type NodeType, and let it point to nothing.
Do the same for variable 'temp'.
Now we put newItem in nothing -> Because that is what newNode is pointing to.
Your program tries to dereference the variable newNode to access its property info. But that's not possible.
This is what your code should be:
NodeType *newNode = new NodeType();
NodeType*temp=nullptr;
newNode->info=newItem;
newNode->next=nullptr;
This way your program has an object to derefer and get a property from.

Answer 2

The code you posted definitely crashes (segmentation fault on Linux or access violation on Windows™) dereferencing the null pointer. You need to create the node before accessing it, like:
NodeType *newNode = new NodeType();