My Linked List

#pragma once

#include <string>
using namespace std;

class node {
public:
    node * next;
    string data;

};

class linkedList {

private:
    node * head;

public:
    linkedList() {
        head = NULL;
    }

    void addFront(string item) {
        node * temp = new node;

        temp->data = item;
        temp->next = head;
        head = temp;
    }

    void addBack(string item) {
        node * temp = new node;
        temp->data = item;
        temp->next = NULL;

        // empty list
        if (head == NULL) {
            head = temp;
        }
        // not empty list
        else {
            node * current = head;

            while (current->next != NULL) {
                current = current->next;
            }
            current->next = temp;
        }
    }

    // returns the first item on the list and removes it
    string pop() {
        string t = head->data;
        node * deleteThis = head;
        head = head->next;
        delete deleteThis;
        return t;
    }

    void remove(string item) {
        if (head == NULL) {

        }
        else if (head->next == NULL) {
            head = NULL;
        }
        else {
            // special cases, if items isnt found
            bool flag = false;

            node * previous = head;
            node * current = head;
            while (current != NULL) {
                if (current->data != item) {
                    current = current->next;
                    if (previous->next != current) {
                        previous = previous->next;
                    }
                }
                else {
                    flag = true;
                    break;
                }
            }
            if (flag) {
                if (current->next == NULL) {
                    previous->next = NULL;
                }
                else {
                    if (previous == head) {
                        head = head->next;
                    }
                    else {
                        previous->next = current->next;
                    }
                }
            }
            else {
                // debugg code
                cout << "item " << item << " wasn't found in the list" << endl;
            }
            delete current;
        }
    }

    // sort the items of the linked list
    void sort() {

        if (head == NULL  || head->next == NULL) {
            // list is either empty, or has one item, no need to sort
        }
        else {
            node * lefter = head;
            node * smallest = head;
            node * zombie = head->next;

            while (lefter != NULL) {
                zombie = lefter;
                while (zombie != NULL) {
                    if (zombie->data < smallest->data) {
                        cout << "smaller one  = " << zombie->data << endl;
                        smallest = zombie;
                    }
                    zombie = zombie->next;
                }

                // switch the values
                string l = lefter->data;
                lefter->data = smallest->data;
                smallest->data = l;

                lefter = lefter->next;
            }
        }
    }

    void display() {
        cout << "\n\n== START OF DISPLAY ==" << endl;
        node * zomb = head;

        while (zomb != NULL) {
            cout << zomb->data << endl;
            zomb = zomb->next;
        }
        cout << "== END OF DISPLAY ==\n\n" << endl;
    }
};