Parameter

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Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Which describes a parameter?

A An identifier in the subroutine definition that receives a value

B The value written in brackets after the subroutine name in a CALL

2. Which line defines a procedure with a parameter?

A PROCEDURE ShowScore(Score : INTEGER)

B PROCEDURE ShowScore(Score)

3. Inside the subroutine, how is a parameter used?

A Only as a constant that can never be read

B Like a variable, for example OUTPUT Score

4. When does a parameter get its value?

A Each time the subroutine is called

B Only once, when the program starts

5. In FUNCTION Double(Num : INTEGER) RETURNS INTEGER, what is Num?

A The value returned by the function

B A parameter with the data type INTEGER

Match the Pairs

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

Left column		Right column
1PROCEDURE Greet(Name : STRING)		ACALL ShowPrice(20)
2FUNCTION Area(Length : INTEGER, Width : INTEGER) RETURNS INTEGER		BThe parameter has no data type. It should be written as Name : STRING.
3A parameter is used like a variable inside the subroutine body		CName is a parameter: an identifier in the definition that receives a value and has the data type STRING
4At each call a value is substituted for the parameter, so Price takes the value 20 here		DPROCEDURE ShowDouble(Num : INTEGER) OUTPUT Num * 2 ENDPROCEDURE
5PROCEDURE Greet(Name)		EFour parameters are used, but this course allows up to three parameters.
6FUNCTION Total(A : INTEGER, B : INTEGER, C : INTEGER, D : INTEGER) RETURNS INTEGER		FLength and Width are two parameters, each receiving a value when Area is called

Definitions

parameter

Fill in the Blanks

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

PROCEDURE ShowDouble(___ : INTEGER) OUTPUT Num * 2 ENDPROCEDURE

PROCEDURE ShowName(Name : ______) OUTPUT "Hello, " & Name ENDPROCEDURE

PROCEDURE Area(Length : REAL, _____ : REAL) OUTPUT Length * Width ENDPROCEDURE

FUNCTION Half(Num : INTEGER) RETURNS REAL RETURN ___ / 2 ENDFUNCTION

PROCEDURE Check(Passed : _______) OUTPUT NOT Passed ENDPROCEDURE

Spot the Error

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

Question 1

A PROCEDURE Greet(Name : STRING)

B OUTPUT "Hi ", Person

C ENDPROCEDURE

D CALL Greet("Sam")

Question 2

A PROCEDURE Sq(Num)

B OUTPUT Num * Num

C ENDPROCEDURE

D CALL Sq(5)

Question 3

A PROCEDURE Show(INTEGER : N)

B OUTPUT "Value: ", N

C ENDPROCEDURE

D CALL Show(7)

Question 4

A PROCEDURE Show(Age : INTEGER)

B OUTPUT "Age: ", "Age"

C ENDPROCEDURE

D CALL Show(15)

Question 5

A PROCEDURE Greet(Name : STRING)

B OUTPUT "Hello ", Name

C ENDPROCEDURE

D CALL Greet(42)

Answer Key

Parameter

Section A: Quick Questions

A — An identifier in the subroutine definition that receives a value

A — PROCEDURE ShowScore(Score : INTEGER)

B — Like a variable, for example OUTPUT Score

A — Each time the subroutine is called

B — A parameter with the data type INTEGER

Section B: Match the Pairs

PROCEDURE Greet(Name : STRING) → Name is a parameter: an identifier in the definition that receives a value and has the data type STRING

FUNCTION Area(Length : INTEGER, Width : INTEGER) RETURNS INTEGER → Length and Width are two parameters, each receiving a value when Area is called

A parameter is used like a variable inside the subroutine body → PROCEDURE ShowDouble(Num : INTEGER) OUTPUT Num * 2 ENDPROCEDURE

At each call a value is substituted for the parameter, so Price takes the value 20 here → CALL ShowPrice(20)

PROCEDURE Greet(Name) → The parameter has no data type. It should be written as Name : STRING.

FUNCTION Total(A : INTEGER, B : INTEGER, C : INTEGER, D : INTEGER) RETURNS INTEGER → Four parameters are used, but this course allows up to three parameters.

Section C: Definitions

parameter — An identifier in a subroutine definition that receives a value when the subroutine is called. It is used like a variable inside the subroutine and has a data type.

Section D: Fill in the Blanks

PROCEDURE ShowDouble(Num : INTEGER)
  OUTPUT Num * 2
ENDPROCEDURE

PROCEDURE ShowName(Name : STRING)
  OUTPUT "Hello, " & Name
ENDPROCEDURE

PROCEDURE Area(Length : REAL, Width : REAL)
  OUTPUT Length * Width
ENDPROCEDURE

FUNCTION Half(Num : INTEGER) RETURNS REAL
  RETURN Num / 2
ENDFUNCTION

PROCEDURE Check(Passed : BOOLEAN)
  OUTPUT NOT Passed
ENDPROCEDURE

Section E: Spot the Error

B — The parameter is called Name, so the body must use Name. Person was never declared, so it holds no value. It should be OUTPUT "Hi ", Name.

A — Every parameter in a subroutine definition needs a data type. It should be PROCEDURE Sq(Num : INTEGER).

A — The parameter name comes first, then a colon, then the data type. It should be PROCEDURE Show(N : INTEGER).

B — Quotes around Age make it plain text, so the word Age is printed. The parameter must be written without quotes to output the value received. It should be OUTPUT "Age: ", Age.

D — The parameter Name has data type STRING, so the value passed in must be a STRING. 42 is an INTEGER. It should be CALL Greet("Sam").