How is a cheat sheet different from the lessons?

A lesson explains an idea the first time you meet it, with the reasoning spelled out. A cheat sheet skips the reasoning and just shows the syntax, grouped so the common cases sort near the top — it is for recalling something you already understood once, not learning it from scratch.

Are the code snippets actually correct?

Every snippet on this site is run for real before publishing — in the same in-browser runtime the playgrounds use — and the comment or output block next to it is the runtime's actual result, not a guess at what it should print.

Why don't all languages have a cheat sheet yet?

Writing one properly means running and checking every snippet against the real runtime, so they are added language by language rather than all at once. More are on the way.

Reference

Cheat sheets

5 fast-scanning syntax references, one per language: variables, strings, collections, control flow, functions, and error handling, all in one page you can search with Ctrl/Cmd+F.

A cheat sheet is not a tutorial. It is for the syntax you have already learned once and cannot quite remember the shape of — every snippet is run against the real runtime before publishing, so what you see is what actually happens.

C cheat sheet

A scannable C reference covering the program skeleton, printf and scanf format specifiers, types and sizeof, operators, control flow, functions, arrays, strings and string.h, pointers, malloc and free, structs, enums and the preprocessor.

JavaScript cheat sheet

A scannable JavaScript reference covering variables, template literals, string and array methods, objects, destructuring, control flow, functions, arrow functions, and common built-ins.

Python cheat sheet

A scannable Python 3 reference covering variables, f-strings, string methods, lists, dicts, sets, tuples, comprehensions, control flow, functions, built-ins, exceptions, and file handling.

SQL cheat sheet

A scannable SQL reference covering SELECT and WHERE, sorting and limiting, aggregates and GROUP BY, joins, subqueries and CTEs, window functions, INSERT, UPDATE and DELETE, transactions, constraints, and the SQLite-specific behaviour behind each one.

TypeScript cheat sheet

A scannable TypeScript reference covering basic types, interfaces and type aliases, arrays and tuples, functions, union and literal types, generics, enums, type narrowing, and the built-in utility types.

Learning from scratch instead?

Start with the free exercise paths — a cheat sheet only helps once the idea is already familiar. Once you know what you are looking for, try it yourself in a playground.

Questions about the cheat sheets

How is a cheat sheet different from the lessons?: A lesson explains an idea the first time you meet it, with the reasoning spelled out. A cheat sheet skips the reasoning and just shows the syntax, grouped so the common cases sort near the top — it is for recalling something you already understood once, not learning it from scratch.
Are the code snippets actually correct?: Every snippet on this site is run for real before publishing — in the same in-browser runtime the playgrounds use — and the comment or output block next to it is the runtime's actual result, not a guess at what it should print.
Why don't all languages have a cheat sheet yet?: Writing one properly means running and checking every snippet against the real runtime, so they are added language by language rather than all at once. More are on the way.