Structured courses with annotated code, diagrams and exercises. Free, in English, with the interface in English and Bahasa Indonesia.
type Item = { name: string; price: number; quantity: number };const cart: Item[] = [ { name: "Notebook", price: 15000, quantity: 2 }, { name: "Pen", price: 5000, quantity: 0 }, { name: "Bag", price: 120000, quantity: 1 },];const lines = cart.filter((item) => item.quantity > 0);1const subtotals = lines.map((item) => item.price * item.quantity);2const total = subtotals.reduce((sum, value) => sum + value, 0);3console.log(total); // 150000filter keeps the items for which the function returns true. Out goes the pen.map turns each item into something new: here, a number.reduce walks the list once and carries a running value forward. Starting at 0 keeps the result a number even for an empty cart.Two beginner courses, one per track. Read them in either order.
Learn the parts of JavaScript you use every day, then add TypeScript so your editor catches mistakes before your users do. Ends with a small typed project.
How language models produce text, what tokens and context are, how to prompt well, and where these systems fall short. No maths degree required.
Languages, types, architecture and the trade-offs behind everyday engineering decisions.
How language models work, how to prompt and integrate them, and where they fall short.
Concept
Each lesson explains one idea in plain language, with the why and the trade-offs in the margin.
Code
Annotated examples you can run, and short exercises with solutions to check yourself.
Build
Courses end with a small project that puts the pieces together into something real.