Pseudocode: OCR Reference Language Conventions

This lesson covers pseudocode and the OCR Exam Reference Language conventions, as required by OCR J277 Section 2.1. Pseudocode is used extensively in the OCR GCSE Computer Science exam, so understanding the OCR reference language is essential.

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What Is Pseudocode?

Pseudocode is a way of writing algorithms that looks like a simplified programming language but is not tied to any specific language. It uses structured, English-like statements to describe the logic of an algorithm.

Pseudocode is:

• Language-independent — It does not follow the syntax of any specific programming language
• Readable — Easier to understand than actual code
• Structured — Uses indentation and keywords to show the logic clearly
• Used in exams — OCR uses its own pseudocode reference language in the exam

OCR Exam Tip: In the exam, pseudocode questions use the OCR Exam Reference Language. You do not need to use perfect syntax, but you should follow the OCR conventions. The reference language guide is available on the OCR website and will be familiar from your practice.

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OCR Pseudocode Conventions

Variables and Assignment

Variables are assigned using =:

name = "Alice"
age = 16
total = 0

Data Types

Data Type	Description	Example
Integer	Whole number	age = 16
Real	Decimal number	price = 9.99
Boolean	True or False	found = true
Character	Single character	grade = 'A'
String	Text (sequence of characters)	name = "Alice"

Arithmetic Operators

Operator	Meaning	Example	Result
+	Addition	3 + 2	5
-	Subtraction	10 - 4	6
*	Multiplication	5 * 3	15
/	Division	10 / 3	3.33...
MOD	Modulus (remainder)	10 MOD 3	1
DIV	Integer division (quotient)	10 DIV 3	3
^	Exponentiation (power)	2 ^ 3	8

OCR Exam Tip: MOD and DIV are commonly tested. MOD gives the remainder (10 MOD 3 = 1), DIV gives the whole number result of division (10 DIV 3 = 3). Learn these well — they appear in many exam questions.

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Input and Output

// Input
name = input("Enter your name: ")

// Output
print("Hello")
print(name)
print("Your score is " + score)

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Selection (IF Statements)

Simple IF:

if score >= 50 then
    print("Pass")
endif

IF...ELSE:

if score >= 50 then
    print("Pass")
else
    print("Fail")
endif

IF...ELSEIF...ELSE:

if score >= 70 then
    print("Distinction")
elseif score >= 50 then
    print("Pass")
else
    print("Fail")
endif

SWITCH/CASE:

switch day:
    case "Monday":
        print("Start of the week")
    case "Friday":
        print("End of the week")
    default:
        print("Midweek")
endswitch

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Iteration (Loops)

FOR Loop (count-controlled):

for i = 1 to 10
    print(i)
next i

FOR Loop with STEP:

for i = 0 to 20 step 2
    print(i)
next i

WHILE Loop (condition-controlled — pre-check):

while answer != "quit"
    answer = input("Enter command: ")
endwhile