Using selection statements

These two examples show extracts of code that make use of selection statements.

The inefficient version makes use of three separate IF statements. As the statements are not related to one another, the program will always execute each line of code. No matter what age is input, all nine lines of code will be executed.

The efficient version makes use of nested IF statements. When using a Nested IF, the first selection statement will run. If it finds that the age entered is higher than 65 then it will not run the second IF statement at all - the nested IF statement is only executed if the first selection statement does not assign a value to the ticketCategory variable.

Inefficient	Efficient
IF age ˃65 THEN	IF age ˃65 THEN
SET ticketCategory TO concession	SET ticketCategory TO concession
END IF	ELSE
IF age˃= 18 AND age ˂=65 THEN	IF age˃17 THEN
SET ticketCategory TO adult	SET TICKETCategory TO adult
END IF	ELSE
IF age˂18 THEN	SET ticketCategory TO child
SET ticketCategory TO child	END IF
END IF	END IF

Inefficient	IF age ˃65 THEN
Efficient	IF age ˃65 THEN

Inefficient	SET ticketCategory TO concession
Efficient	SET ticketCategory TO concession

Inefficient	END IF
Efficient	ELSE

Inefficient	IF age˃= 18 AND age ˂=65 THEN
Efficient	IF age˃17 THEN

Inefficient	SET ticketCategory TO adult
Efficient	SET TICKETCategory TO adult

Inefficient	END IF
Efficient	ELSE

Inefficient	IF age˂18 THEN
Efficient	SET ticketCategory TO child

Inefficient	SET ticketCategory TO child
Efficient	END IF

Inefficient	END IF
Efficient	END IF

EvaluationUsing selection statements

Using selection statements

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