Why is this printing an infinite loop?

#pragma once

#include

#include

template

class LinkedList

{

public:

LinkedList();

~LinkedList();

int getLength();

void print();

void add(Type);

void remove(Type);

int length;

struct Node

{

Type val;

Node* next;

};

Node* head, *tail;

};

/**

* Sets head and tail to null, sets length to be empty.

*/

template

LinkedList::LinkedList()

{

head = tail = NULL;

length = 0;

}

/**

* Destructor for the Linked List.

*/

template

LinkedList::~LinkedList()

{

Node* prev = NULL;

Node* it = head;

while (it != NULL)

{

prev = it;

it = it->next;

delete prev;

}

}

/**

* Prints the whole linked list.

*/

template

void LinkedList::print()

{

int index = 0;

Node* it = head;

while (it != NULL)

{

std::cout << "{" << index << ":" << it->val << "}";

if (it->next != NULL)

{

std::cout << ", ";

}

it = it->next;

}

}

/**

* @return the number of nodes in the linked list.

*/

template

int LinkedList::getLength()

{

return length;

}

template

void LinkedList::add(Type value)

{

Node* newNode = new Node;

newNode->val = value;

newNode->next = NULL;

if (head == NULL)

{

head = tail = newNode;

}

else

{

tail->next = newNode;

tail = newNode;

}

length++;

}

/**

* Removes all nodes that have the value passed in.

* @param value The value you want to remove.

*/

template

void LinkedList::remove(Type value)

{

Node* it = head;

Node* prev = NULL;

while (it->next != NULL)

{

if (it->val == value)

{

if (prev == NULL)

{

head = it->next;

delete it;

}

else

{

prev->next = it->next;

delete it;

}

}

prev = it;

it = it->next;

}

length--;

}