09/23/05 CISC181 

An aside:
  cout << "enter x: " << flush;
  cin >> x;

The flush means put the characters to the
screen right away, with no delay.

If there isn't a flush, the program is
allowed to "procrastinate" doing I/O
becuase I/O takes such a long time to do.
Calculation is so much faster.

So the program will sometimes "batch up"
all of its I/O, storing it in a buffer
until the buffer is full, or some "event"
happens that makes you need to do it
right away, such as an invocation of "flush".

It turns out that when you do cin >> x;
a flush happens on cout automatically.
So putting flush on cout in this case is
redundant.

\n       only writes a newline

endl     writes a newline AND does a flush



Option a:

  cout << "Hello Kitty" << endl;
  cout << "What's new Pussycat" << endl;
  cout << "Whoa Whao Whao Whao." << endl;

Option b:
  cout << "Hello Kitty\n" ;
  cout << "What's new Pussycat\n" 
  cout << "Whoa Whao Whao Whao." << endl;