C++ Pointers

pointers.cpp

    int x = 0;
    int* ptr;
    x = 10;
    ptr = &x; // Save address of x into ptr
    cout << "X = " << x << endl; // Result is 10
    cout << "Y = " << *ptr << endl; // Result is 10

    // ============

    struct TwoNumbers { 
           int x;
           int y;
    };

    TwoNumbers numbers;
    TwoNumbers* nptr;

    numbers.x = 5;
    numbers.y = 9;

    nptr = &numbers; // Save address of numbers into nptr

    cout << "Numbers.x = " << nptr->x << endl; // Result is 5
    cout << "Numbers.y = " << nptr->y << endl; // Result is 9

    // ============

    int* a;
    int b[2];
    a = b; // Now a points to first element of b
    b[0] = 7;
    b[1] = 10;
    *a++; // Here a is incremented (not the first element of b), so now a points to second element of b
    cout << *a << endl; // Result is 10 (second element of b)

    // ============

    int* aaa;
    int bbb = 7;
    aaa = &bbb; // Save address of bbb into aaa
    bbb += 7; // Now bbb is 14
    (*aaa)++; // Here we increment variable at address kept in aaa (this is bbb), so bbb now is 15
    cout << aaa << endl; // Result is address kept in aaa
    cout << *aaa << endl; // Result is 15