2. The IF Statement
 Use the IF statement to control if a part of the program
executes. If the condition is TRUE, one set of one or
more statement executes; and if the condition is
FALSE, another set of one or more statements executes
 IF <Boolean expression> THEN <statement>
 IF Amount < 0 THEN
Amount := -Amount;

3. IF - THEN - ELSE
 IF <Boolean expression> THEN
<statement 1>
ELSE
<statement 2>
IF Quantity <> 0 THEN
UnitPrice := TotalPrice / Quantity
ELSE
UnitPrice := 0;
;

4. The EXIT Statement
 Code in a trigger executes sequentially from the top to
the bottom
 IF Quantity = 0 THEN
EXIT;
UnitPrice := TotalPrice / Quantity;

5. Code Indentation
 To indent several lines of code, select the lines, and
then press TAB.
 To indent several lines of code to the left, select those
lines, and press SHIFT+TAB

6. The CASE Statement
 Use the CASE conditional statement when there are
more than two possible values for the condition.
 CASE <expression> OF
<value set 1> : <statement 1>;
<value set 2> : <statement 2>;
<value set n> : <statement n>;
[ELSE <statement n+1>]
END

7. CASE Example
Number:=25;
CASE Number OF
1,2,9: MESSAGE('1, 2, or 9.');
10..100: MESSAGE('In the range from 10 to 100.');
ELSE
MESSAGE('Neither 1, 2, 9, nor in the range from 10 to 100.');
END;
Output: In the range from 10 to 100

8. Compound Statements and Comments
 A compound statement is multiple statements
 A comment is a description that developers write in
their code .
 // this code comment
 {
line 1
line 2
line 3
}

9. The Syntax of Compound Statements
 BEGIN <statement> {; <statement>} END
 IF Quantity <> 0 THEN
BEGIN
UnitPrice := ExtendedPrice / Quantity;
TotalPrice := TotalPrice + ExtendedPrice;
END;

10. IF Quantity <> 0 THEN
BEGIN
UnitPrice := ExtendedPrice / Quantity;
TotalPrice := TotalPrice + ExtendedPrice;
END //No ;
ELSE
BEGIN
UnitPrice := 0;
EXIT;
END; // ;

11. Compound Statement by Using Nested IF Statements
IF Amount <> 0 THEN
IF Amount > 0 THEN
Sales := Sales + Amount
ELSE
IF Reason = Reason::Return THEN
IF ReasonForReturn = ReasonForReturn::Defective THEN
Refund := Refund + Amount
ELSE
Credits := Credits + Amount
ELSE
Sales := Sales - Amount;

12. To have organized code
 Use correct indentation.
 Use meaningful variable names
 Do not use negative variable names (for example,
DoNotDelete
 Use Booleans to designate Yes or No choices.

13. Demonstrations
 Demonstration: Use the Conditional and Compound
Statements in a Page (Page 12)
 Practice: Nested IF (Page 21)
 Lab 6.1: Use Conditional and Compound Statements
(Page 23)

14. Arrays
 Arrays are complex variables that contain a group of
variables with the same data type.
 Simple data types only have a single value.
 A complex data type has multiple values.
 Number array with 10 elements
10 5 4 50 21 63 20 12 42 25

15. Form 223

16. How to clear Variable
 CLEAR(<variable>);
 For example, for a one-dimensional array named
SaleAmount of type Decimal, use the following
function call to set all elements in SaleAmount to zero
 CLEAR(SaleAmount);

17. Array Element Syntax
 <identifier>[<index expression>{,<index expression>}]
 Box[5] := 25;

18. ARRAYLEN Function
 In your array you have seven elements but you are
trying to access 8th index Then you will get a run time
error .
 Result := ARRAYLEN(<array variable>)
 ARRAYLEN(SaleAmount)
 IF Counter <= ARRAYLEN(SaleAmount) THEN
SaleAmount[Counter] := Answer;

19. Strings as Arrays of Characters
 Str := ‘Walk in the park’;
Str[13] := ‘d’;
MESSAGE(Str);
Output :Walk in the dark

20. Repetitive Statements
 A repetitive statement is a statement that enables execution
of one or more statements multiple times.
 The FOR Statement
FOR <control variable> := <start value> TO <end value> DO
<statement>
FOR idx := 4 TO 8 DO
Total := Total + 2.5;
FOR <control variable> := <start value> DOWNTO <end value> DO
<statement>
FOR Number:= 10 DOWNTO 5 DO
MESSAGE(FORMAT(Number));

21. The WHILE...DO Statement
 WHILE <Boolean expression> DO <statement>
 When Boolean Expression is true statement is
executed. And if the expression is False statement
skipped.

22. The REPEAT...UNTIL Statement
 Use the REPEAT statement when one or more statements
are to be executed until some condition becomes true.
 REPEAT
<statement> { ; <statement> }
UNTIL <Boolean expression>
Number :=10;
REPEAT
MESSAGE(FORMAT(Number));
Number:=Number-1;
UNTIL Number=2.;

23. WITH Statement
 When you work with records, addressing is created as
record name, dot (period), and field name:
 <Record>.<Field>
 If you work continuously with the same record, then
you can use WITH statements. When you use a WITH
statement, you only specify the record name once.

24. WITH Statement
CustomerRec."No." := '1234';
CustomerRec.Name := 'Windy City Solutions';
CustomerRec."Phone No." := '555-444-333';
CustomerRec.Address := '1241 Druid Avenue';
CustomerRec.City := 'Windy City'; MESSAGE('A variablehas been created for this
customer.');
WITH CustomerRec DO BEGIN
"No." := '1234';
Name := 'Windy City Solutions';
"Phone No." := '555-444-333';
Address := '1241 Druid Avenue';
City := 'Windy City'; MESSAGE('A variable has been created for this customer.');
END;

25. Demonstrations
 Demonstration: Use Arrays and Repetitive Statements