Programming Concepts

Question 1

What is a variable?

Answer 1

A variable is an identifier that can change in the lifetime of a program.

Question 2

What are the four variable requirements?

Answer 2

• In mixed case (Pascal case)
• Only contain letters (A-Z, a-z)
• Only contain digits (0-9)
• Start with a capital letter and not a digit

Question 3

Example variable declaration

Answer 3

DECLARE GameOver : BOOLEAN

Question 4

What is a constant

Answer 4

A constant is an identifier set once in the lifetime of a program generally named in all uppercase letters.

Question 5

INTEGER

Answer 5

Whole numbers: 5, 0, -5

Question 6

REAL

Answer 6

Numbers with a fractional part (decimal): 3.14, -2.5, 0.0

Question 7

CHAR

Answer 7

Single character: ‘a’, ‘B’, ‘6’, ‘£’

Question 8

STRING

Answer 8

Sequence of characters: “Hello world”, “ABC”, “@#!%”

Question 9

BOOLEAN

Answer 9

True or false values: True, False

Question 10

INPUT and OUTPUT example

Answer 10

INPUT Answer
OUTPUT “Your answer is”, Answer

Question 11

What is sequence?

Answer 11

• Sequence is when lines of code run one after another in the order they are written, from first to last.
• It is essential for the correct flow of a program — instructions out of order can cause errors or unexpected results.

Question 12

IF Statements syntax

Answer 12

IF Answer ← “Yes”
THEN
OUTPUT “Correct”
ELSE
OUTPUT “Wrong”
ENDIF

Question 13

CASE OF Statements syntax

Answer 13

INPUT Move

CASE OF Move
‘W’ : Position ← Position - 10
‘E’ : Position ← Position + 10
‘A’ : Position ← Position - 1
‘D’ : Position ← Position + 1
OTHERWISE
OUTPUT “Beep”
ENDCASE

Question 14

What are the two type of selection statements?

Answer 14

• IF Statements
• CASE OF Statements

Question 15

What are the two type of condition - controlled loops?

Answer 15

• While Loops
• Repeat Until Loops

Question 16

What is an example of a count - controlled loop?

Answer 16

• FOR Loops

Question 17

FOR Statements syntax

Answer 17

FOR X ← 1 TO 10
OUTPUT “Hello”
NEXT X

Question 18

WHILE Loops syntax

Answer 18

INPUT Temperature
WHILE Temperature > 37 DO
OUTPUT “Patient has a fever”
INPUT temperature
END WHILE

Question 19

REPEAT UNTIL Statements Syntax

Answer 19

REPEAT
INPUT Colour
UNTIL Colour ← “red”

Question 20

Totalling Syntax

Answer 20

Total ← 0
FOR I ← 1 to 10
INPUT Num
TOTAL ← TOTAL + Num
NEXT I
OUTPUT Total

Question 21

Counting Syntax

Answer 21

Count ← 0
FOR I ← 1 to 10
INPUT Num
IF Num > 5
THEN
Count ← Count + 1
ENDIF
NEXT I
OUTPUT Count

Question 22

String Handling Uppercase

Answer 22

Name ← “Sarah”
OUTPUT UCASE(Name)

Question 23

String Handling Lowercase

Answer 23

Name ← “SARAH”
OUTPUT LCASE(Name)

Question 24

String Handling Length

Answer 24

Password ← “letmein”
OUTPUT LENGTH(Password)

Question 25

String Handling Substring

Answer 25

Word ← "Revision" OUTPUT SUBSTRING(Word, 1, 3)

Question 26

Logical Operators

Answer 26

- = (equal to) - < (less than) - <= (less than or equal to) - > (greater than) - >= (greater than or equal to) - <> (not equal to)

Question 27

BOOLEAN Operators

Answer 27

- AND: Returns True if both conditions are True - OR: Returns True if one or both conditions are True - NOT: Returns the opposite of the condition (True if False, False if True)

Question 28

Arithmetic Operators

Answer 28

- DIV (10 , 3) returns 3 (whole number division) - MOD (10 , 3) returns (Remainder after division) - * (Multiplication Operator)

Question 29

What's the difference between a function and procedure?

Answer 29

A Function returns a value whereas a procedure does not.

Question 30

What are parameters?

Answer 30

Parameters are values that are passed into a sub program.

Question 31

Uses of subroutines

Answer 31

- Avoid duplicating code and can be reused throughout a program - Improve the readability and maintainability of code - Perform calculations, to retrieve data, or to make decisions based on input

Question 32

What are procedures and functions?

Answer 32

Functions and procedures are a type of sub program, a sequence of instructions that perform a specific task or set of tasks.

Question 33

Procedure Syntax

Answer 33

PROCEDURE CalculateArea(length: INTEGER, width: INTEGER) area ← length * width OUTPUT "The area is ",area END PROCEDURE

Question 34

Calling a Procedure

Answer 34

CALL CalculateArea CALL CalculateArea(5,3)

Question 35

Function Syntax

Answer 35

FUNCTION calculate_area(length: INTEGER, width: INTEGER) RETURNS INTEGER area ← length * width RETURN area ENDFUNCTION // Output the value returned from the function inside the subroutine OUTPUT(calculate_area(5,3))

Question 36

Local Variables

Answer 36

- A variable declared inside a specific scope (like a function or code block). - It’s accessible only within that block and is destroyed once the block finishes executing.

Question 37

Global Variables

Answer 37

- A variable declared outside all functions or procedures. - It has global scope, meaning it can be accessed and modified from anywhere in the program.

Question 38

Library Routines

Answer 38

A piece of reusable, pre-written code made available through modules or functions that can be used in different parts of a program.

Question 39

Two examples of library routines

Answer 39

- ROUND - RANDOM

Question 40

RANDOM Syntax

Answer 40

# Outputs 1.95 RANDOM(1,6)

Question 41

ROUND Syntax

Answer 41

Cost ← 1.9556 OUTPUT ROUND(Cost,2) # Outputs 1.95

Question 42

Ways to maintain a program

Answer 42

**Use comments** - to explain the purpose of each section of code - for example, logic / syntax **Use meaningful identifier names to** - clearly identify the purpose - of variables, constants, arrays, procedures **Use procedures and functions** - to avoid repeated code - simplify logic **Use indentation and white space** - to make the program readable