The FOR loop is for situations in which a statement or series of statements must be repeated 0 or more times--the
exact number of times being known before the loop begins. In contrast, loops based on the WHILE and REPEAT/UNTIL
statements are better suited to circumstances in which the terminating condition must be calculated in the loop
(that is, in which the number of times to repeat isn't known in advance).
Syntax:
FOR <ordinalVar>
:= <ordinalExpr> {TO|DOWNTO} <ordinalExpr>
DO
<statement>
For example, this loop outputs 'Hello' ten times (N is an integer variable):
for N :=
1 to
10 do Writeln('Hello');
The DOWNTO keyword causes the counter variable to be decremented with each pass, as in this program:
program
ForDemo;
uses
Win32Crt;
var N
: integer;
begin
Write('Ignition sequence has commenced ...');
for
N := 10 downto
1 do
begin
Write(N, '...');
Delay(1000);
end;
Writeln('Blastoff!');
end. { ForDemo }
