Comments with // (8.1a)

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Which line is a correct comment in Cambridge pseudocode?

A Store the player's score //

B // Store the player's score

2. What happens to the text after // when the program runs?

A It is run as code

B It is ignored

3. Which program prints the same output as the other three when the comment is removed? Pick the statement that is true about comments.

A Adding a comment does not change what the program does

B Adding a comment changes the value stored in the variable

4. Which line puts a short comment at the end of a line of code?

A Total ← Price * 3 // cost of 3 items

B Total ← Price * 3 cost of 3 items

5. A comment needs to explain code that runs over two lines. Which is correct?

A // Calculate the total cost // including the delivery fee

B // Calculate the total cost including the delivery fee

Match the Pairs

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

Left column		Right column
1// Calculate the area		AThe second line of the comment is missing //, so it would be treated as code and cause an error.
2Total ← Price * Qty // cost of items		BA statement followed by an end-of-line comment: the assignment runs but the comment is ignored
3A comment that spans several lines needs // at the start of every line		CA comment on its own line that explains the code below it and is ignored when the program runs
4Adding a comment does not change what the program does, so the program still outputs 10		DA single slash does not start a comment. It must be two slashes //, otherwise the text is treated as code and causes an error.
5Score ← 0 / set score to zero		E// Program to find the average // Input three marks and output the mean
6// Ask the user for a name and store it in Name INPUT Name		FX ← 10 // set X to ten OUTPUT X

Definitions

Fill in the Blanks

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

__ Set the starting score Score ← 0

Total ← Price * Quantity __ cost of items

// Calculate the area of a rectangle __ Width and Height are in cm Area ← Width * Height

______ Total // show the final total

Lives _ 3 // player starts with 3 lives

Spot the Error

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

Question 1

A // Store the player's score

B DECLARE Score : INTEGER

C Score ← 0 # start at zero

D OUTPUT Score

Question 2

A / Ask for the user's name

B DECLARE Name : STRING

C INPUT Name

D OUTPUT "Hello ", Name

Question 3

A CONSTANT Pi ← 3.142

B INPUT Radius

C // Work out the circle area

D // Area ← Pi * Radius ^ 2

E OUTPUT Area

Question 4

A DECLARE Lives : INTEGER

B Lives ← // starting lives 3

C OUTPUT Lives

Question 5

A // Program: temperature check

B // Written for Year 10

C Converts C to F

D INPUT Celsius

E OUTPUT Celsius * 9 / 5 + 32

Answer Key

Comments with // (8.1a)

Section A: Quick Questions

B — // Store the player's score

B — It is ignored

A — Adding a comment does not change what the program does

A — Total ← Price * 3 // cost of 3 items

A — // Calculate the total cost // including the delivery fee

Section B: Match the Pairs

// Calculate the area → A comment on its own line that explains the code below it and is ignored when the program runs

Total ← Price * Qty // cost of items → A statement followed by an end-of-line comment: the assignment runs but the comment is ignored

A comment that spans several lines needs // at the start of every line → // Program to find the average // Input three marks and output the mean

Adding a comment does not change what the program does, so the program still outputs 10 → X ← 10 // set X to ten OUTPUT X

Score ← 0 / set score to zero → A single slash does not start a comment. It must be two slashes //, otherwise the text is treated as code and causes an error.

// Ask the user for a name and store it in Name INPUT Name → The second line of the comment is missing //, so it would be treated as code and cause an error.

Section C: Definitions

// — Starts a comment. Everything after // on that line explains the code to people and is ignored when the program runs, so it never changes what the program does.

Section D: Fill in the Blanks

// Set the starting score
Score ← 0

Total ← Price * Quantity // cost of items

// Calculate the area of a rectangle
// Width and Height are in cm
Area ← Width * Height

OUTPUT Total // show the final total

Lives ← 3 // player starts with 3 lives

Section E: Spot the Error

C — Cambridge pseudocode comments start with //, not #. The line should be Score ← 0 // start at zero.

A — A comment needs two forward slashes. A single / is not a comment, so the words would be read as code. It should be // Ask for the user's name.

D — The // turned the calculation into a comment, so it never runs and Area has no value. The calculation should be Area ← Pi * Radius ^ 2 with no // before it. The comment belongs on its own line above.

B — Everything after // is ignored, so the 3 is now part of the comment and the assignment has no value. The comment must go after the code: Lives ← 3 // starting lives.

C — In a multi-line comment, every line must start with //. Without it, this line is treated as code. It should be // Converts C to F.