C++ Pointer Sample

#include <iostream>

struct Node {
    int value = 0;
    Node* previous = nullptr;
    Node* next = nullptr;
};

struct List {
    List(){
        head = new Node();
        tail = head;
    }
    ~List(){
        std::cout << "Destructor: " << std::endl;
        Node* current = head;
        while (current != nullptr){
            Node* next = current->next;
            std::cout << "Deleting: " << current->value << std::endl;
            delete current;
            current = next;
        }
    }
    void Append(int value){
        Node* previous = tail;
        tail = new Node();
        tail->value = value;
        tail->previous = previous;
        previous->next = tail;
    }

    void Print(){
        std::cout << "Printing the List:" << std::endl;
        Node* current = head;
        for (Node* current = head; current != nullptr;current = current->next){
            std::cout << current->value << std::endl;
        }
    }
    Node* tail;
    Node* head;
};

void main(){
    int a = 5; //variable named a has a value of 5.
    int *pA = &a; //pointer named pA is now referencing the memory address of a (we reference "a" with & to get the address).

    std::cout << *pA << ", " << a << std::endl; //output 5, 5
    a = 6;
    std::cout << *pA << ", " << a << std::endl; //output 6, 6
    *pA = 7;
    std::cout << *pA << ", " << a << std::endl; //output 7, 7

    int b = 20;
    pA = &b;
    std::cout << *pA << ", " << a << ", " << b << std::endl; //output 20, 7, 20
    *pA = 25;
    std::cout << *pA << ", " << a << ", " << b << std::endl; //output 25, 7, 25
    pA = &a;
    std::cout << *pA << ", " << a << ", " << b << std::endl; //output 7, 7, 25
    *pA = 8;
    std::cout << *pA << ", " << a << ", " << b << std::endl; //output 8, 8, 25
    b = 30;
    pA = &b;
    std::cout << *pA << ", " << a << ", " << b << std::endl; //output 30, 8, 30

    char text[] { 'H', 'e', 'l', 'l', 'o', '\0' };
    char* letter = text;

    for (char* letter = &text[0]; *letter != '\0';++letter){
        std::cout << "[" << *letter << "]";
    }
    std::cout << std::endl;
    {
        List sampleList;
        sampleList.Append(5);
        sampleList.Append(6);
        sampleList.Append(7);
        sampleList.Append(8);
        sampleList.Print();
    }
    system("PAUSE");
}