SECTION(4, Tutorial 4)
m5_question(Study the following code:
m4_begin_indent
NU()CLASS CLSS(LoopTest) EOL
BEGIN EOL
PD FUNCTION INT FUNC(powerOf2A)(INT VARI(n)) EOL
PD BEGIN EOL
PD PD VAR INT VARI(counter) = n; EOL
PD PD VAR INT VARI(result) = NUMB(1); EOL
PD PD WHILE (counter != NUMB(0)) EOL
PD PD BEGIN EOL
PD PD PD result = NUMB(2) * result; EOL
PD PD PD counter = counter - NUMB(1); EOL
PD PD END EOL
PD PD RETURN result; EOL
PD END EOL
EOL
PD FUNCTION INT FUNC(powerOf2B)(INT VARI(n)) EOL
PD BEGIN EOL
PD PD VAR INT VARI(counter) = n; EOL
PD PD VAR INT VARI(result) = NUMB(1); EOL
PD PD DU EOL
PD PD BEGIN EOL
PD PD PD result = NUMB(2) * result; EOL
PD PD PD counter = counter - NUMB(1); EOL
PD PD END WHILE (counter != NUMB(0)); EOL
PD PD RETURN result; EOL
PD END EOL
EOL
PD FUNCTION INT FUNC(powerOf2C)(INT VARI(n)) EOL
PD BEGIN EOL
PD PD VAR INT VARI(result); EOL
PD PD VAR INT VARI(counter); EOL
PD PD FUR (counter = n, result = NUMB(1); counter != NUMB(0); counter = counter - NUMB(1)) EOL
PD PD BEGIN EOL
PD PD PD result = NUMB(2) * result; EOL
PD PD END EOL
PD PD RETURN result; EOL
PD END EOL
EOL
PD COMM( EOL
PD /** EOL
PD * Prints a row of stars of a given length. EOL
PD */) EOL
PD FUNCTION VOID FUNC(printLineC)(INT VARI(length)) EOL
PD BEGIN EOL
PD PD FUR (VAR INT VARI(i) = NUMB(0); LT(i,length); i=i+NUMB(1)) EOL
PD PD BEGIN EOL
PD PD PD SYSTEM_OUT_PRINT(STRI("HASH")); EOL
PD PD END EOL
PD PD SYSTEM_OUT_PRINTLN(); EOL
PD END EOL
EOL
PD BEGIN_MAIN EOL
PD PD COMM(// For question 4.1 add some code here...) EOL
PD END_MAIN EOL
END EOL
m4_end_indent
)
m5_question(BO(Question 4.1:) To the MAIN function add some
code to call the functions TT(powerOf2A), TT(powerOf2B) and
TT(powerOf2C) to verify that they all return the same result. To
inspect the result you will need to apply the SYSTEM_OUT_PRINTLN
statement to the values returned by those functions.)
m5_question(BO(Question 4.2:) There is a bug in the TT(powerOf2B) method
because it does not behave correctly in the case when n is zero.
Put an EM(if) statement at the top of this method to make it
handle the case of zero properly.)
m5_question(BO(Question 4.3:) By copying the pattern of
TT(powerOf2A), TT(powerOf2B) and TT(powerOf2C), write methods
TT(printLineA) and TT(printLineB) that work identically to the method
TT(printLineC), except that they use EM(while) loops and EM(do) loops,
respectively. Add some code to the MAIN function to test them out.
)
m5_question(BO(Question 4.4:) Based on the previous three
questions, is there a best looping construct? Or does it depend on
what the looping construct is going to be used for?)
