Learn to code

Code

Write real code and see it run — HTML, CSS, Python, Java, C, SQL, LaTeX, and Linux — with nothing to install.

10 coursesHTML/CSS · Python · Java · C · SQL · LaTeX · LinuxRuns in your browser

Foundations

Python Basics

Your very first steps in programming — no experience needed.

15 Lessons

A short history of Python

What Python is used for

Dictionaries (records)

Planning & pseudocode

Errors & testing

Putting it all together

JavaScript

The language of the web. Make things happen — runs right in your browser.

15 Lessons

A short history of JavaScript

What JavaScript is used for

Where to learn more

Run JavaScript anywhere

console.log and comments

Variables — let and const

Numbers and maths

Strings

Template literals

Booleans and comparisons

C Programming

From printf to pointers, memory, and data structures — compile and run in your browser.

23 Lessons

C basics: main, printf, and functions

Variables, types, and arithmetic

Booleans and selection: if, else, switch

Loops: while, for, and accumulation

Functions, parameters, and return values

Nested loops and patterns

1-D arrays: store, index, and traverse

Pointers: &, *, and pass-by-pointer

Strings: char arrays and the null terminator

Array algorithms: max, count, search, average

2-D arrays: working with a grid

Searching: linear and binary

Sorting: bubble, selection, and insertion

Recursion: base case and recursive case

Structs and typedef: . vs ->

Dynamic memory: malloc, free, and realloc

Linked lists

Stacks and queues (array-backed)

Text files: write then read

Error handling with return codes

Bits, binary, and bitwise operators

Run-length encoding (compression)

Preprocessor, const, static, and enum

Web Basics — HTML & CSS

Start from zero. Short steps. Build a real web page.

21 Lessons

A short history of the web

What a web page is made of

Where to learn more

What you need (almost nothing)

Your first web page

Headings and paragraphs

Bold, italic and line breaks

Comments and neat nesting

Selectors — class and id

Colours and backgrounds

Styling text

The box model

Spacing — margin and padding

Showing and hiding (display)

Width and centering

Rows with Flexbox

Mini-project: a profile card

Exam courses

Python for IGCSE CS

Programming, algorithms, databases and logic for Cambridge IGCSE 0478.

14 Lessons

Sequence, input & output

Variables, constants & data types

Selection — IF and CASE

Iteration — loops

Totalling & counting

Procedures & functions

Validation & verification

1-D arrays (lists)

2-D arrays

Searching & max / min

Bubble sort

Text files

Databases & SQL

Boolean logic & truth tables

Python for A-Level CS

Data structures, algorithms, and OOP for Cambridge 9618.

15 Lessons

Nested loops & 2-D lists

Inheritance & encapsulation

Programming paradigms

Hash tables

Binary search trees

Graphs

Cambridge Pseudocode

Write and run the pseudocode used in IGCSE 0478 and A-Level 9618 exam answers.

14 Lessons

OUTPUT and sequence

Variables and DECLARE

INPUT and data types

Arithmetic, DIV and MOD

Selection: IF

Selection: CASE

Iteration: FOR

Iteration: WHILE and REPEAT

Python for AP CS Principles

Big ideas of computing — data, algorithms, the Internet, and impact.

15 Lessons

What computing is

Bits and binary

Data compression

Variables and expressions

Lists and data abstraction

Selection

Iteration

Procedures and abstraction

Algorithms: searching

Randomness and simulation

Algorithmic efficiency

The Internet and how data travels

Parallel and distributed computing

Impact of computing

The Create Performance Task (guided)

Java for AP CS A

Java programming for the AP Computer Science A exam.

19 Lessons

A short history of Java

What Java is used for

Where to learn more

Set up your computer

Java basics: classes, main, and output

Using objects: String, Math, and wrappers

Booleans and selection: if/else and logic

Loops: while, for, and accumulation

Strings and nested loops

Writing a class: fields, constructor, methods

Encapsulation: private fields, getters, setters

1-D arrays: store, index, and traverse

Array algorithms: max, count, search, average

ArrayList: a list that grows

ArrayList algorithms: filter and the remove bug

2-D arrays: working with a grid

Searching: linear and binary

Sorting: selection and insertion sort

Recursion: base case and recursive case

Text files: write and read with Scanner

Inheritance: extends, super, and overriding

Polymorphism: dynamic dispatch and toString()

FRQ workshop: the 4 question types

Topics & tools

Databases & SQL

Query, design, and change relational databases — right in your browser, no setup.

17 Lessons

A short history of SQL

Sorting with ORDER BY

Counting and averaging

LIKE, IN and BETWEEN

Grouping with GROUP BY

Tables, keys and relationships

Linux & the command line

Drive a computer by typing. Practise real shell commands in a safe in-browser terminal.

14 Lessons

What is Linux?

Why learn the command line?

Helpful resources

Get a real terminal

The shell and the prompt

Moving around

Reading files

Creating and removing

Wildcards

Saving output to files

Pipes — joining commands

Searching with grep

Finding files with find

Sorting and columns

File permissions

Users and sudo

Programs and processes

Software, settings, next steps

LaTeX

Typeset beautiful documents and maths — write LaTeX, compile on our servers, see the PDF.

14 Lessons

What is LaTeX?

Where LaTeX is used

Helpful resources

Use LaTeX on your own computer

Your first document

Sections and titles

Bold, italic and emphasis

Bulleted and numbered lists

Maths — your first formula

Fractions, roots and sums

Aligning equations

Tables

Drawing with TikZ

Labels and cross-references

Citations and bibliography

Page layout and margins

Colour and links

Capstone: a one-page report

Cyber security

How attacks work and how to stop them — ciphers, hashing, and safe computing, hands-on.

16 Lessons

What is cyber security?

Why it matters

Helpful resources

Nothing to install

Security, privacy and integrity

Malware

Attacks and brute force

Social engineering

Defending a system

Passwords and authentication

Storing passwords safely

Encoding is not encryption

Symmetric encryption

Asymmetric encryption

Hashing and digital signatures

HTTPS, SSL/TLS and certificates

Data integrity

SQL injection

Access control and least privilege

Ethics, law and staying safe

Practice

Sharpen your skills with challenges from 1★ to 5★. Pick a language.

Print a bigger number

Multiply two variables

Flatten a nested list

Reverse the word order

Most frequent character

★★★☆☆

Binary search

★★★☆☆

Factorial (mind the size)

Longest common prefix

Multiply two variables

Greatest common divisor

Code

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Where to learn more

Practice

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