Writing exam answers about procedures and functions

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Which is the correct Cambridge pseudocode header for a function that gives back a whole number?

A FUNCTION Double(n : INTEGER) RETURN INTEGER

B FUNCTION Double(n : INTEGER) RETURNS INTEGER

2. Which line correctly ends a function?

A ENDFUNCTION

B ENDPROCEDURE

3. Which statement inside a function body sends the value back to the caller?

A RETURNS Total

B RETURN Total

4. Which is the correct way to use the function Area in a program?

A OUTPUT Area(5.0)

B CALL Area(5.0)

5. Which exam sentence defines a function correctly?

A A subroutine that returns a value to the part of the program that called it.

B A subroutine that never sends a value back to the program.

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1FUNCTION Double(n : INTEGER) RETURNS INTEGER		AThe header of a function: RETURNS gives the data type of the value sent back to the caller
2ENDPROCEDURE		BCALL ShowMenu()
3A procedure is run with the CALL keyword, and it does not return a value		Ctotal ← AddTax(price)
4A function sends a value back with RETURN, so its call is used inside an expression, not with CALL		DThe header is missing RETURNS REAL, so the data type of the returned value is not stated.
5CALL Area(5.0)		EThe keyword that closes a procedure; a function is closed with ENDFUNCTION instead
6FUNCTION Area(r : REAL) RETURN r * r * 3.14 ENDFUNCTION		FCALL is used with a function. Functions return a value, so the call should be used in an expression such as result ← Area(5.0).

Definitions

RETURNS

Fill in the Blanks

Complete each line of code by filling in the missing parts.

FUNCTION Area(r : REAL) _______ REAL

FUNCTION IsEven(n : INTEGER) RETURNS _______ RETURN n MOD 2 = 0 ENDFUNCTION

PROCEDURE ShowScore(s : INTEGER) OUTPUT s ____________

FUNCTION Square(n : INTEGER) RETURNS INTEGER ______ n * n ENDFUNCTION

____ ShowScore(85)

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A FUNCTION Pi() RETURN REAL

B RETURN 3.14

C ENDFUNCTION

Question 2

A PROCEDURE ShowMenu()

B OUTPUT "1. Play"

C ENDFUNCTION

Question 3

A DECLARE score : INTEGER

B score ← 0

C score ← CALL GetScore()

D OUTPUT score

Question 4

A FUNCTION Pi() RETURNS REAL

B OUTPUT 3.14

C ENDFUNCTION

Question 5

A PROCEDURE Greet(n : STRING)

B OUTPUT "Hi ", n

C ENDPROCEDURE

D Greet("Sam")

Answer Key

Writing exam answers about procedures and functions

Section A: Quick Questions

B — FUNCTION Double(n : INTEGER) RETURNS INTEGER

A — ENDFUNCTION

B — RETURN Total

A — OUTPUT Area(5.0)

A — A subroutine that returns a value to the part of the program that called it.

Section B: Match the Pairs

FUNCTION Double(n : INTEGER) RETURNS INTEGER → The header of a function: RETURNS gives the data type of the value sent back to the caller

ENDPROCEDURE → The keyword that closes a procedure; a function is closed with ENDFUNCTION instead

A procedure is run with the CALL keyword, and it does not return a value → CALL ShowMenu()

A function sends a value back with RETURN, so its call is used inside an expression, not with CALL → total ← AddTax(price)

CALL Area(5.0) → CALL is used with a function. Functions return a value, so the call should be used in an expression such as result ← Area(5.0).

FUNCTION Area(r : REAL) RETURN r * r * 3.14 ENDFUNCTION → The header is missing RETURNS REAL, so the data type of the returned value is not stated.

Section C: Definitions

RETURNS — Keyword in a FUNCTION header giving the data type of the value sent back, e.g. FUNCTION Area(r : REAL) RETURNS REAL. End with ENDFUNCTION. Never use CALL for a function.

Section D: Fill in the Blanks

FUNCTION Area(r : REAL) RETURNS REAL

FUNCTION IsEven(n : INTEGER) RETURNS BOOLEAN
  RETURN n MOD 2 = 0
ENDFUNCTION

PROCEDURE ShowScore(s : INTEGER)
  OUTPUT s
ENDPROCEDURE

FUNCTION Square(n : INTEGER) RETURNS INTEGER
  RETURN n * n
ENDFUNCTION

CALL ShowScore(85)

Section E: Spot the Error

A — The function header must use the keyword RETURNS (with an S) before the data type. It should be FUNCTION Pi() RETURNS REAL. RETURN is only used inside the body to send the value back.

C — A procedure must be closed with ENDPROCEDURE, not ENDFUNCTION. Each block ends with the keyword that matches the one that started it.

C — CALL is only used for procedures. A function is used in an expression, so the line should be score ← GetScore().

B — A function must send its value back with RETURN. OUTPUT only displays a value and returns nothing. It should be RETURN 3.14.

D — A procedure must be run using the keyword CALL. It should be CALL Greet("Sam").