Scottish examsHigher

SQA reference language for Computing Science: what the exam code means

Published 12 Nov 20268 min read

National 5 Computing Science

Higher Computing Science

Papers reset in

Formula sheet

It is a document, not a sheet in the exam: SQA publishes it and the papers use it. The card below opens today's Higher Computing Science paper with our summary in the drawer, so you can check what a construct means while you read the code. The summary follows in our own layout and words, grouped by what the code does. Check it against the full SQA document, dated September 2016, before you rely on it.

Formula sheet

National 5 Computing Science

Open formula sheet

Types and values

Reference language	What it means	Level
INTEGER, REAL, BOOLEAN, CHARACTER	The base types: whole numbers, decimals, true or false, and a single character	All
STRING	Text, which is an array of characters	All
ARRAY OF INTEGER	A list of values that are all of one type	All
[ 10, 20, 30 ]	An array value, with the first item at position 0	All
RECORD Person IS { STRING name, INTEGER age }	A named record type, with one value for each field	Higher, Advanced Higher
{ name = "Fred", age = 42 }	A record value	Higher, Advanced Higher

Variables and assignment

Reference language	What it means	Level
DECLARE total INITIALLY 0	Creates a variable and gives it a starting value	All
DECLARE x AS INTEGER INITIALLY 0	The same, with the type written out	All
SET total TO total + 1	Changes the value of a variable that exists	All

Conditions

Reference language	What it means	Level
IF .. THEN .. END IF	Runs the commands only when the condition is true	All
IF .. THEN .. ELSE .. END IF	Chooses between two sets of commands	All

Loops

Reference language	What it means	Level
WHILE .. DO .. END WHILE	Repeats while the condition is true, checked before each pass	All
REPEAT .. UNTIL ..	Repeats until the condition is true, checked after each pass	All
REPEAT 5 TIMES .. END REPEAT	Repeats a fixed number of times	All
FOR i FROM 0 TO 9 DO .. END FOR	Counts from the start value to the end value	All
FOR i FROM 0 TO 9 STEP 3 DO .. END FOR	The same, in steps of 3	All
FOR EACH item FROM list DO .. END FOR EACH	Goes through every value in an array or other collection	All

Input and output

Reference language	What it means	Level
RECEIVE x FROM KEYBOARD	Reads a value into an existing variable	All
DECLARE x INITIALLY FROM KEYBOARD	Creates a variable from the first value read	All
SEND x TO DISPLAY	Shows a value	All
OPEN, CLOSE, CREATE	File operations	Higher, Advanced Higher

Operations

Reference language	What it means	Level
+ - * / ^	Add, subtract, multiply, divide and raise to a power	All
MOD	The remainder after a division	All
&	Joins strings, as in "Total: " & total	All
= ≠ < ≤ > ≥	Comparisons	All
AND OR NOT	Logical operators	All

Subprograms

Reference language	What it means	Level
move( sprite, "up", 0.5 )	A call to a subprogram, with its parameters in brackets	All
PROCEDURE id ( parameters ) .. END PROCEDURE	A subprogram that does something and returns nothing	Higher, Advanced Higher
FUNCTION id ( parameters ) RETURNS type .. RETURN expression .. END FUNCTION	A subprogram that returns a value	Higher, Advanced Higher

Object-oriented programming

Reference language	What it means	Level
CLASS .. IS { .. } METHODS .. END CLASS	Defines a class with its fields and methods	Advanced Higher
CLASS .. INHERITS .. WITH { .. } METHODS .. END CLASS	Defines a subclass	Advanced Higher
CONSTRUCTOR .. END CONSTRUCTOR	The method that creates an object	Advanced Higher
OVERRIDE CONSTRUCTOR .. END CONSTRUCTOR	A constructor in a subclass that replaces the parent's	Advanced Higher

Comments and elisions

Reference language	What it means	Level
# a comment	A note for the reader, ignored by the program	All
< .. >	An elision: part of the code written in English, not in the reference language	All

What the reference language is not

Not a language you must write. The specifications say candidates are not expected to write code in the reference language, and that answers may use any programming language. Marks are for demonstrating understanding, not for correct syntax.
Not a list of every function. A question may use its own subprograms, such as getColour or move, and says what they do. The language only gives the shape of the code.
Not formal for everything. The elision < .. > lets a question describe part of the code in English.
Not a replacement for knowledge. To explain what a program does, you still need to understand loops, arrays, records, standard algorithms and (at Advanced Higher) objects.

How the papers use the reference language

The course specifications say the questions assessing programming are expressed in the reference language. In the 2027 timetable all three papers are on Thursday 27 May: National 5 from 09:00 to 10:30, Higher from 09:00 to 11:00, and Advanced Higher from 09:00 to 11:00 (Exam Timetable 2027, version 02). The specifications give the question paper 80 marks at National 5, 80 at Higher and 55 at Advanced Higher. Our guides cover the courses: National 5, Higher and Advanced Higher.

Reading reference language under exam pressure

Read the declarations first, so you know every variable and its starting value.
Work through the loop by hand, with a table of the variables after each pass.
Check the loop condition: WHILE tests before a pass and REPEAT UNTIL tests after one.
Write what the program does in one sentence, then answer the question in that sentence.

Tracing a loop

What does this code display?

DECLARE marks INITIALLY [ 45, 62, 58, 71 ]
DECLARE total INITIALLY 0
FOR EACH mark FROM marks DO
   SET total TO total + mark
END FOR EACH
SEND "Average: " & total / 4 TO DISPLAY

FOR EACH takes each value in marks in turn. Keep a table of total after each pass:

Pass	mark	total after the pass
1	45	45
2	62	107
3	58	165
4	71	236

Then 236 ÷ 4 = 59, so the program displays Average: 59. The & joins the text to the number. In words, it finds the average of four marks.

A condition inside a loop

What does this code display?

DECLARE count INITIALLY 0
FOR n FROM 1 TO 10 DO
   IF n MOD 3 = 0 THEN
      SET count TO count + 1
   END IF
END FOR
SEND count TO DISPLAY

MOD gives the remainder, so n MOD 3 = 0 is true when n is a multiple of 3. Between 1 and 10 those are 3, 6 and 9, so count is 3 and the program displays 3. It counts the multiples of 3.

Practise tracing code in the Search Algorithms course, then press Mark.

Press Mark to have your answer marked in the Search Algorithms course.

Exam answers

The answers and a worked mark scheme come with today's paper once it is marked. Sit the paper with the sheet open beside you, mark it, and the worked answers show which line each question wanted. We do not publish official or past paper answers.

Use the sheet with today's paper

Uni-Sine publishes a free daily paper for National 5 Computing Science and Higher Computing Science. It is a short timed paper of 8 questions worth 25 to 35 marks, not a full SQA paper and not set by SQA. Many schools set a longer prelim in winter: see our prelims guide. Open the sheet, set a timer, and write the line you use at the start of each answer.

Common mistakes

Skipping the trace. Guessing the output from the code's shape loses marks. Write the variables out after each pass.
Mixing up WHILE and REPEAT UNTIL. WHILE can run zero times. REPEAT UNTIL always runs at least once.
Starting at 1. Array positions start at 0, as in allTimes[ 0 ].
Ignoring the declaration. The starting value of total changes every answer.
Describing the lines instead of the purpose. Say what the program is for, such as finding the average or counting multiples.

Common questions

What is the SQA reference language?

It is the standard notation SQA uses to present code in National 5, Higher and Advanced Higher Computing Science question papers. It is written in capitals, such as DECLARE and FOR EACH.

Do I have to write in the SQA reference language?

No. The specifications say candidates are not expected to write code in it, and that you can use any programming language. Marks are for understanding, not for correct syntax.

Is the reference language the same as pseudocode?

SQA's document says earlier versions called it pseudocode, but it prefers reference language, because it is formally defined.

Does Advanced Higher use more of the reference language?

Yes. It adds classes, inheritance and constructors for object-oriented programming. Higher adds records, files, procedures and functions to what National 5 uses.

Where can I read the SQA reference language?

SQA's document Reference language for Computing Science question papers is on the Qualifications Scotland website, dated September 2016.

Revision cards

Say the answer first, then flip the card to check it.

Where to go next

Solve it
Code Editor
Write and run code right in your browser
Open the tool
Learn it
Search Algorithms
Linear, binary, depth-first and beyond: find data fast with the right algorithm
Start the course
Test it
National 5 Computing Science
A new exam-style paper every day, with instant marking and a mark scheme
Start today's paper

SQA reference language for Computing Science: what the exam code means

National 5 Computing Science

Higher Computing Science

Formula sheet

National 5 Computing Science

Types and values

Variables and assignment

Conditions

Loops

Input and output

Operations

Subprograms

Object-oriented programming

Comments and elisions

What the reference language is not

How the papers use the reference language

Reading reference language under exam pressure

Tracing a loop

A condition inside a loop

Exam answers

Use the sheet with today's paper

Common mistakes

Common questions

Revision cards

Where to go next

Code Editor

Search Algorithms

National 5 Computing Science