while loop: example 2

program whileloop2;

{
  This program demonstrates a "while" loop.  It
  continually asks the user to enter a number
  until that number is 0.
}

var
  n : integer;  { the number entered by user }

begin
  write('Enter a number: ');
  readln(n);

  while n <> 0 do
    begin
      writeln('The number you entered is ', n);
      { Ask for another number }
      write('Enter a number: ');
      readln(n);
    end;
end.

Below we show a compilation and run of the program.

% pc whileloop2.p

% a.out
Enter a number: 4
The number you entered is          4
Enter a number: 7
The number you entered is          7
Enter a number: 0