Complete IGCSE Computer Science Revision Notes: Programming

Programming is a core component of IGCSE Computer Science. These comprehensive revision notes cover programming fundamentals, data structures, algorithms, and programming techniques, providing everything you need to master programming for Cambridge and Edexcel IGCSE Computer Science.

Programming Fundamentals

Variables and Data Types

• Integer: whole numbers
• Real/Float: decimal numbers
• String: text
• Boolean: true/false
• Character: single character

Input and Output

• Input: getting data from user
• Output: displaying results
• Formatting output
• User-friendly interfaces

Operators

• Arithmetic: +, -, *, /, MOD, DIV
• Comparison: =, <>, <, >, <=, >=
• Logical: AND, OR, NOT
• Assignment: ← or =

Control Structures

Selection (If Statements)

• IF…THEN…ELSE
• Nested IF statements
• CASE/SWITCH statements
• Conditions and Boolean expressions

Iteration (Loops)

• FOR loops: fixed number of iterations
• WHILE loops: condition-based
• REPEAT…UNTIL loops
• Nested loops

Examples:

FOR i = 1 TO 10
    OUTPUT i
NEXT i

WHILE condition
    // code
ENDWHILE

Data Structures

Arrays

• One-dimensional arrays
• Two-dimensional arrays
• Indexing: array[index]
• Uses: storing lists of data

Lists

• Dynamic arrays
• Adding/removing items
• Searching lists
• Sorting lists

Records/Structures

• Grouping related data
• Field access: record.field
• Uses: storing complex data
• Examples: student records

Algorithms

Searching Algorithms

• Linear search: check each item
• Binary search: divide and conquer (sorted data)
• Efficiency comparison
• When to use each

Sorting Algorithms

• Bubble sort: compare adjacent items
• Insertion sort: insert in correct position
• Efficiency comparison
• Implementation

Validation

• Input validation
• Range checks
• Type checks
• Format checks

Functions and Procedures

Functions

• Return a value
• Can take parameters
• Reusable code
• Examples: mathematical functions

Procedures

• Perform actions
• May take parameters
• No return value
• Examples: display procedures

Parameters

• Passing data to functions/procedures
• By value vs by reference
• Local vs global variables
• Scope

File Handling

Reading from Files

• Opening files
• Reading data
• Processing data
• Closing files

Writing to Files

• Creating files
• Writing data
• Appending data
• Closing files

File Operations

• Checking if file exists
• Error handling
• File formats
• Data validation

Exam Tips

1. Practice Pseudocode

• Learn syntax
• Practice reading code
• Practice writing code
• Trace through algorithms

2. Understand Algorithms

• Know how algorithms work
• Practice implementing
• Understand efficiency
• Apply to problems

3. Debugging Skills

• Identify errors
• Trace through code
• Test with examples
• Fix errors systematically

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Use these revision notes as part of your comprehensive exam preparation. Combine with past paper practice and expert tutoring for best results.