Description |
The Until keyword ends a control loop that is always executed at least once, and which terminates when the Expression is satisfied (returns True).
There is no need for Begin or End markers - the Repeat and Until keywords serve that purpose.
It is used when it is important that the statements are at least executed once.
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Notes |
The last Statement need not have a ; terminator - it is entirely optional.
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Related commands |
Begin |
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Keyword that starts a statement block |
Boolean |
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Allows just True and False values |
Do |
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Defines the start of some controlled action |
End |
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Keyword that terminates statement blocks |
For |
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Starts a loop that executes a finite number of times |
Repeat |
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Repeat statements until a ternmination condition is met |
While |
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Repeat statements whilst a continuation condition is met |
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Example code : Display integer squares until we reach or exceed 100 |
var
num, sqrNum : Integer;
begin
num := 1;
sqrNum := num * num;
// Display squares of integers until we reach 100 in value
Repeat // Show the square of num
ShowMessage(IntToStr(num)+' squared = '+IntToStr(sqrNum));
// Increment the number
Inc(num);
// Square the number
sqrNum := num * num;
Until sqrNum > 100;
end;
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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
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