2.2 Programming Concepts

Question 1

State the 5 programming 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

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

Answer 23

• 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 24

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

Answer 24

• 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 25

What is an array?

Answer 25

• Collection of variables of the same data type
• Referred to by a single name (identifier)
• Each element is accessed by an index (position)
• Often called a data structure

Question 26

What are the advantages of an array?

Answer 26

+ can store multiple values under a single identifier
+ reduces the number of variables
+ can use iteration to loop through an array
+ allows for more efficient programming

Question 27

What is a subroutine?

Answer 27

A subroutine is a block of code that is given a name.

Question 28

State 2 types of subroutine

Answer 28

Function and Procedure

Question 29

What is the difference between a function and a procedure

Answer 29

Function – A subroutine that always returns a value.
Procedure – A subroutine that may or may not return a value.

Question 30

What is a library routine?

Answer 30

Library routine – A prewritten subroutine to carry out common tasks (it is available for immediate use)

Question 31

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 31

Question 32

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 32

Question 33

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

Answer 33

Question 34

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 34

Question 35

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 35

Question 36

Write an algorithm that asks the user to enter 10 names and stores them into an array called names.

It should then output the names in reverse order

Answer 36

Question 37

Write an algorithm that searches through an array of integers named nums to find the highest value and the average of all of the numbers stored. The array stores 100 numbers.

Your program should then output the highest value.

Answer 37