MEMORY:
      |       |
 addr |       |
      |       |
      |=======|
  123 |x: 72  |<---
      |=======|    \
      |       |     |
      |       |     |
      |       |     |
      |       |     |
      |=======|    /
      |p: 123------
      |=======|
      |       |
      |       |
      |       |
      |       |






--------------------------
float x = 5, y = 9;
float *p = &x, *q = &y;
*p = 17.0;
*q = *p;     // y = 17
q = p;      // q points to whatever p points to
            //  (copy the memloc value)
*q = 13.0;
cout << x << endl;
cout << y << endl;
--------------------------
 p---->x: 13
 q-----^             y: 17

PREDICT THE OUTPUT:
  13
  17





---------------------------------
int x = 10, y = 15;

int *a = &x;
cout << x << " " << y << endl;

int *b = &y;   // int *b;  b = &y;
*a = x * *b;  // 10 * 15 = 150
cout << x << " " << y << endl;

int *c = b;  // int *c;  c = b;
*c = 25;
cout << x << " " << y << endl;
---------------------------------
  a--->x: 150
  b--->y: 25
       ^
       |
       c

PREDICT THE OUTPUT:
  10 15
  150 15
  150 25






 int x = 0;
 int *m = NULL;

 cout << *m << endl;   // CRASH!









     [0]
     -------------------------------
a--->|  |  |  |  |  |  |  |  |  |  |
     -------------------------------
         ^
         p

            p++  ==>  p = p + sizeof( double )








Define a new data type:
(1) attributes
(2) operations on those attributes

class Employee
{
private:
  string lname, fname;
  int id;
  string addr1, addr2, city, state, zip;

public:
  // constructors

  // accessor functions

  // mutator functions
};


 // in main()
 Date d1();
 Date d2( 1, 1, 2003 );

 if ( d1.isEqual( d2 ) ) {
   // dates are equal!
 }

 if ( d1.isLeapYear() ) { // ... }