Coding Sheets, Practice & Learning Support: Quick Reference Pseudocode Sheet For AS Level (Copy)

Quick Reference Pseudocode Sheet For AS Level

Purpose Of This Sheet

• Designed as a fast lookup / revision sheet
• Contains:
  • Core pseudocode structures
  • Standard patterns repeatedly used in exams
• Meant to be:
  • Memorised
  • Reproduced quickly under exam pressure
• All pseudocode follows Cambridge-style conventions

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Basic Syntax Rules (Must Follow)

Assignment

variable ← value

Input / Output

INPUT variable
OUTPUT variable

Comparison Operators

Meaning	Operator
Equal to	=
Not equal	<>
Greater than	>
Less than	<
Greater or equal	>=
Less or equal	<=

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Selection (IF Statements)

IF Only

IF condition THEN
  statement
ENDIF

IF–ELSE

IF condition THEN
  statement1
ELSE
  statement2
ENDIF

Nested IF

IF condition1 THEN
  IF condition2 THEN
    statement
  ENDIF
ENDIF

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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

Iteration (Loops)

FOR Loop (Fixed Count)

FOR i ← 1 TO n
  statement
NEXT i

WHILE Loop (Entry-Controlled)

WHILE condition DO
  statement
ENDWHILE

REPEAT UNTIL Loop (Exit-Controlled)

REPEAT
  statement
UNTIL condition

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Validation Templates

Range Validation (REPEAT UNTIL)

REPEAT
  INPUT value
UNTIL value >= min AND value <= max

Option Validation

REPEAT
  INPUT option
UNTIL option = 1 OR option = 2 OR option = 3

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Counters And Accumulators

Counter Template

count ← 0

FOR i ← 1 TO n
  IF condition THEN
    count ← count + 1
  ENDIF
NEXT i

Accumulator Template

total ← 0

FOR i ← 1 TO n
  INPUT value
  total ← total + value
NEXT i

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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

Average Calculation

Average Of All Values

total ← 0

FOR i ← 1 TO n
  INPUT value
  total ← total + value
NEXT i

average ← total / n
OUTPUT average

Average Of Selected Values

total ← 0
count ← 0

FOR i ← 1 TO n
  INPUT value
  IF condition THEN
    total ← total + value
    count ← count + 1
  ENDIF
NEXT i

IF count > 0 THEN
  average ← total / count
  OUTPUT average
ENDIF

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Maximum And Minimum

Maximum

INPUT value
max ← value

FOR i ← 2 TO n
  INPUT value
  IF value > max THEN
    max ← value
  ENDIF
NEXT i

OUTPUT max

Minimum

INPUT value
min ← value

FOR i ← 2 TO n
  INPUT value
  IF value < min THEN
    min ← value
  ENDIF
NEXT i

OUTPUT min

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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

Sentinel-Controlled Input

REPEAT UNTIL Sentinel

REPEAT
  INPUT value
  IF value <> sentinel THEN
    PROCESS value
  ENDIF
UNTIL value = sentinel

WHILE Sentinel

INPUT value
WHILE value <> sentinel DO
  PROCESS value
  INPUT value
ENDWHILE

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Flag Variables

Detection Flag

flag ← FALSE

FOR i ← 1 TO n
  IF condition THEN
    flag ← TRUE
  ENDIF
NEXT i

Early Exit Using Flag

flag ← FALSE
i ← 1

WHILE i <= n AND flag = FALSE DO
  IF condition THEN
    flag ← TRUE
  ELSE
    i ← i + 1
  ENDIF
ENDWHILE

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Arrays

One-Dimensional Array Declaration

DECLARE arr : ARRAY[1..n] OF INTEGER

Input Into Array

FOR i ← 1 TO n
  INPUT arr[i]
NEXT i

Traversing Array

FOR i ← 1 TO n
  PROCESS arr[i]
NEXT i

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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

Linear Search

found ← FALSE
i ← 1

WHILE i <= n AND found = FALSE DO
  IF arr[i] = target THEN
    found ← TRUE
  ELSE
    i ← i + 1
  ENDIF
ENDWHILE

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Bubble Sort (Ascending)

FOR pass ← 1 TO n - 1
  FOR j ← 1 TO n - pass
    IF arr[j] > arr[j + 1] THEN
      temp ← arr[j]
      arr[j] ← arr[j + 1]
      arr[j + 1] ← temp
    ENDIF
  NEXT j
NEXT pass

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String Handling

String Length

length ← LENGTH(text)

Character Access

char ← text[i]

Character-by-Character Processing

FOR i ← 1 TO LENGTH(text)
  PROCESS text[i]
NEXT i

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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

Nested Loops

FOR row ← 1 TO rows
  FOR col ← 1 TO cols
    PROCESS table[row][col]
  NEXT col
NEXT row

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Input–Process–Output Master Skeleton

initialise variables

REPEAT / FOR / WHILE
  INPUT
  IF condition THEN
    PROCESS
  ENDIF
END LOOP

FINAL CALCULATION
OUTPUT

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Common Exam Reminders (Ultra-High Yield)

• Initialise all variables
• Validate before processing
• Use flags for detection, counters for quantity
• Sentinel values must not be processed
• Keep logic simple and structured