int month;

 // ...

 switch ( month )    // only applies to ==
 {
   case 1:
     cout << "January";
     break;
   case 2:
     cout << "February";
     break;
   case 3: case 27:
     cout << "March";
     break;
   // ...

   default:
     cerr << "ERROR: Invalid month!" << endl;
 }






 ********
 *      *
 * D    *
 *  a   *
 *   v  *
 *    e *
 *      *
 ********






 l-values
 r-values

  string a = "Kim";
  string b = "Tom";
  b[1] = a[1];

  cout << a << '\n' << b << endl;

  l-value = r-value

  (x + y) = j;










 Constructing vectors:

 vector<int> a;  // empty vector -- use push_back()

 vector<double> b( 100, 3.1415 );
       // create a vector with 100 "slots"
       //  assign each to 3.1415
       //  use push_back() to keep adding ...

 int n = 100;
 vector<int> c( n * n );
       // create vector of integers
       //   size 10000
       //  use push_back() to keep adding ...

 vector<double> d( b );
       // "copy constructor"
       // create a new vector by first creating
       //   a vector of size b, then COPYING all
       //   elements from b

 vector<int> e( d );
       // "copy constructor"
       // 

 vector<vector<int>> x;   // try this out?








  ifstream ==> input file stream

  ofstream ==> output file stream

  ofstream outfile( "output.txt" );
  // ofstream is the type
  // outfile is the variable name
  // output.txt is the filename

  outfile << "this is some output" << endl;

  int x = 5;
  outfile << x;