Queue Data structure app crash with front() method - c++

Question

I am implementing a queue data structure, but my app crashes. I know I am doing something wrong with Node pointer front or Front() method of queue class
#include <iostream>
using namespace std;
class Node
{
public:
int get() { return object; };
void set(int object) { this->object = object; };
Node * getNext() { return nextNode; };
void setNext(Node * nextNode) { this->nextNode = nextNode; };
private:
int object;
Node * nextNode;
};
class queue{
private:
Node *rear;
Node *front;
public:
int dequeue()
{
int x = front->get();
Node* p = front;
front = front->getNext();
delete p;
return x;
}
void enqueue(int x)
{
Node* newNode = new Node();
newNode->set(x);
newNode->setNext(NULL);
rear->setNext(newNode);
rear = newNode;
}
int Front()
{
return front->get();
}
int isEmpty()
{
return ( front == NULL );
}
};
main()
{
queue q;
q.enqueue(2);
cout<<q.Front();
system("pause");
}

Answer 1

You're using uninitialized pointers on several occasions.
Enqueue refers to rear->setNext(). If the queue is empty, rear is uninitialized, leading to crashes.
Front returns the node by some Node member-function without checking for a non-null pointer. Why not simply return the *front pointer?
None of your classes have a constructor. Your pointers aren't even NULL-pointers, they're just uninitialized. That's asking for troubles.
My advice:
Give both classes a constructor.
When calling ANY Node member-function, check for valid pointers.
Use less Node member-functions; returns raw pointers when you can.