Pseudocode Foundations & Conventions: Cambridge AS Level Pseudocode Rules And Conventions (Copy)

Cambridge AS Level Pseudocode Rules And Conventions

Purpose And Exam Context (Paper 2 Focus)

• Pseudocode is the only accepted answer style for Paper 2
• Marks are awarded for:
  • Correct logic
  • Clear structure
  • Proper use of Cambridge-style constructs
• Syntax precision matters less than logic, but conventions matter a lot
• Answers must be:
  • Language-neutral
  • Step-by-step
  • Easy for an examiner to trace

Core Structural Rules (Must-Follow)

Assignment, Comparison And Operators

Variable Declaration And Initialisation

• Always initialise:
  • Counters
  • Totals
  • Flags
• Uninitialised variables = logic error

Constants (Fixed Values)

• Use constants when a value never changes
• Improves readability and avoids magic numbers

Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change AS Level Computer Science Full Scale Course

Input And Output Conventions

• Always label outputs
• Never use PRINT / READ (language-specific)

IF Selection Structures (Fully Guided)

Simple IF

IF Age >= 18 THEN
    OUTPUT "Eligible"
ENDIF

IF–ELSE

IF Score >= 50 THEN
    OUTPUT "Pass"
ELSE
    OUTPUT "Fail"
ENDIF

Nested IF

IF Age >= 18 THEN
    IF HasID = TRUE THEN
        OUTPUT "Allowed"
    ELSE
        OUTPUT "ID Required"
    ENDIF
ELSE
    OUTPUT "Underage"
ENDIF

CASE Selection (Menu-Style Logic)

INPUT Choice
CASE Choice OF
    1 : OUTPUT "Add"
    2 : OUTPUT "Delete"
    3 : OUTPUT "Search"
    OTHERWISE : OUTPUT "Invalid"
ENDCASE

Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change AS Level Computer Science Full Scale Course

Loop Structures (Decision Guide)

FOR Loop (Count-Controlled)

Total ← 0
FOR i ← 1 TO 10
    INPUT Value
    Total ← Total + Value
ENDFOR
OUTPUT "Total = ", Total

WHILE Loop (Pre-Condition)

Count ← 0
WHILE Count < 5 DO
    INPUT Num
    Count ← Count + 1
ENDWHILE

• Condition checked before loop runs

REPEAT UNTIL Loop (Post-Condition)

REPEAT
    INPUT Age
UNTIL Age >= 0 AND Age <= 120

• Loop runs at least once
• UNTIL condition ends the loop

Procedures (Task-Based Logic)

PROCEDURE DisplayResult(Mark : INTEGER)
    IF Mark >= 50 THEN
        OUTPUT "Pass"
    ELSE
        OUTPUT "Fail"
    ENDIF
ENDPROCEDURE

CALL DisplayResult(Score)

Functions (Value-Returning Logic)

FUNCTION GetAverage(Total : INTEGER, Count : INTEGER) RETURNS REAL
    RETURN Total / Count
ENDFUNCTION

Average ← GetAverage(Sum, N)

Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change AS Level Computer Science Full Scale Course

Arrays (1D And 2D)

Traversing 1D Array

FOR i ← 1 TO 30
    Total ← Total + Marks[i]
ENDFOR

Traversing 2D Array

FOR r ← 1 TO 10
    FOR c ← 1 TO 10
        OUTPUT Grid[r,c]
    ENDFOR
ENDFOR

Linear Search (Flag-Controlled Pattern)

Found ← FALSE
i ← 1

WHILE i <= N AND Found = FALSE DO
    IF A[i] = Target THEN
        Found ← TRUE
    ELSE
        i ← i + 1
    ENDIF
ENDWHILE

IF Found THEN
    OUTPUT "Found at ", i
ELSE
    OUTPUT "Not Found"
ENDIF

Records (Structured Data)

RECORD StudentType
    Name : STRING
    Age : INTEGER
    Score : INTEGER
ENDRECORD

DECLARE Student : StudentType
Student.Name ← "Ali"
Student.Score ← 85

Text File Handling (AS Scope)

OPENFILE DataFile FOR READ

WHILE NOT EOF(DataFile) DO
    READFILE DataFile, Line
    OUTPUT Line
ENDWHILE

CLOSEFILE DataFile

Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change AS Level Computer Science Full Scale Course

Common Exam Traps And Fixes

Safe Exam Skeleton (Reusable)

DECLARE variables
Initialise variables

INPUT values

Process logic

OUTPUT results