8.1 Programming Concepts

Question 1

State the 5 data types you need to know

Answer 1

INTEGER
STRING
REAL
CHAR
BOOLEAN

Question 2

Describe, giving an example, the data type INTEGER

Answer 2

Stores a whole number e.g. 3, 45,‐453

Question 3

Describe, giving an example, the data type STRING

Answer 3

Stores zero or more sequence of characters e.g. “Bob”, “44-0151”, “:)”

Question 4

Describe, giving an example, the data type REAL

Answer 4

Stores integers and numbers with a decimal part e.g. 3 , 3.2, -9.11

Question 5

Describe, giving an example, the data type CHAR

Answer 5

Stores a single character (a letter, digit, punctuation mark or symbol) e.g. ‘a’, ‘#’, ‘9’

Question 6

Describe, giving an example, the data type BOOLEAN

Answer 6

Stores only 2 possible values e.e. true (1) or false (0)

Question 7

What is a variable?

Answer 7

A variable is named memory location that can store a value.
The value can change whilst the program is running.

Question 8

What is a constant?

Answer 8

A constant is a named value.
The value cannot change whilst the program is running.

Question 9

What are the advantages of constants?

Answer 9

The code will be easier to read and understand (because the constant’s identifier will be used instead of a number)
When its value changes, you only have to edit it in one place.
The value cannot be accidentally changed during the running of the program.

Question 10

Explain the Pseudocode key words MOD and DIV and give an example

Answer 10

DIV = whole number part of division
17 DIV 5 = 3

MOD = the remainder part of division
17 MOD 5 = 2

Question 11

Describe, giving an example in pseudocode, the term “counting”

Answer 11

Counting is used to count the number of items in a list.
Count is usually incremented by 1

count ← count + 1

Question 12

Describe, giving an example in pseudocode, the term “totalling”

Answer 12

Totalling is used to sum a list of numbers.
Each values is added to a running total.

total ← total + value

Question 13

What is sequencing?

Answer 13

Sequencing is the idea of one statement or instruction being executed one after another

Question 14

Describe, giving an example in pseudocode, the term “selection”

Answer 14

Selection decides which statements are executed based on a condition e.g.

IF age >= 18 THEN
OUTPUT “You can vote”
ENDIF

Question 15

What are the 2 types of conditional statement you need to know

Answer 15

IF … THEN … ELSE … ENDIF
CASE … OF … OTHERWISE … ENDCASE

Question 16

Describe the conditional statement CASE … OF … OTHERWISE … ENDCASE and give a reason why you would use it

Answer 16

Description: A statement that allows for multiple selections/deals with many possible outcomes
Reason: To simplify pseudocode and make it easier to read

Question 17

Describe the pseudocode statement IF … THEN … ELSE … ENDIF

Answer 17

A conditional statement …
… with different outcomes for true and false

Question 18

Convert the following C# code into pseudocode

Console.Write(“Enter item: “);
item = Console.ReadLine();

Answer 18

OUTPUT “Enter item: “
INPUT item

Question 19

Convert the following C# code into pseudocode

Console.Write(“Enter price:”);
price = double.Parse(Console.ReadLine());

Answer 19

OUTPUT “Enter price:”
INPUT price

Question 20

Which datatype should be used to store the following data

Address
Height (m)
Grade (A to F)
Price
Age
Married
Telephone Number

Answer 20

Address: STRING
Height (m): REAL
Grade (A to F): CHAR
Price: REAL
Age: INTEGER
Married: BOOLEAN
Telephone Number: STRING

Question 21

What are the 3 loop (iteration) structures you need to know?

Answer 21

FOR … TO … NEXT
WHILE … DO … ENDWHILE
REPEAT … UNTIL

Question 22

Describe the FOR … TO … NEXT loop structure and state when you would you it

Answer 22

• A loop that will iterate a set number of times.
• Used when you know how many times you want to iterate.

Question 23

Write an algorithm that asks the user to enter a score (integer). If it is below 50 it should output “Fail”. If it is 50 to 64 it should ouput “Pass”. If it is 65 or above it should output “Merit”

Answer 23

Question 24

Write an algorithm using a case statement that asks the user to enter an integer. If the number entered is 1 or 2 it should output “one” or “two” respectively. Otherwise it should output “unknown”.

Answer 24

Question 25

Write an algorithm that totals the numbers 1 to 100 and outputs the total.

Answer 25

Question 26

Write an algorithm using pseudocode to:

• input a positive integer
• use this value to set up how many other numbers are to be input
• input these numbers
• calculate and output the average of these numbers

Answer 26

Question 27

Describe the WHILE … DO … ENDWHILE loop structure and state when you would use it

Answer 27

• A condition-controlled loop.
• Condition is checked at the start of the loop.
• The code inside the loop may therefore not execute.
• Used when you do not know how many times to iterate.

Question 28

Describe the REPEAT … UNTIL loop structure and state when you would you it

Answer 28

• A condition-controlled loop.
• Condition is checked at the end of the loop.
• The code inside the loop will always execute at least once.
• Used when you do not know how many times to iterate.

Question 29

Write an algorithm that asks the user to guess a name. It should keep asking the user until the name Turing is entered.

You must use a WHILE … DO … ENDWHILE loop

Answer 29

Question 30

Write an algorithm that asks the user to guess a password. It should keep asking the user until the name password 1L0v3Marm1t3 is entered.

You must use a REPEAT … UNTIL loop

Answer 30

Question 31

What makes a maintainable program?

Answer 31

• Meaningful identifier names for variables, constants, arrays, procedures and functions
• The problem is broken down into appropriate subroutines (functions and procedures)
• It should be fully commented to explain/document the code for yourself and others