Description

The While keyword
starts a control loop that is executed as long as
the Expression is satisfied
(returns True).
The loop is not executed at all if the expression
is false at the start.
You need Begin or
End markers if multiple statements
are required in the loop.
It is used when it is important that the statements
are at only executed when necessary.


Related commands

Begin


Keyword that starts a statement block

Boolean


Allows just True and
False values

Do


Defines the start of some controlled action

End


Keyword that terminates statement blocks

For


Starts a loop that executes a finite number
of times

Repeat


Repeat statements until a ternmination
condition is met

Until


Ends a Repeat control loop





Example code : Display
integer squares until we reach 100

var
num, sqrNum : Integer;
begin
num := 1;
sqrNum := num * num;
//
Display squares of integers until we reach 100 in
value
While sqrNum
<= 100 do
begin
// Show the square of
num
ShowMessage(IntToStr(num)+'
squared = '+IntToStr(sqrNum));
// Increment the
number
Inc(num);
// Square the
number
sqrNum := num * num;
end;
end;

Show full unit code

1 squared = 1
2 squared = 4
3 squared = 9
4 squared = 16
5 squared = 25
6 squared = 36
7 squared = 49
8 squared = 64
9 squared = 81
10 squared = 100

