Tuples & labeled tuples
Learn about tuples: arrays with fixed length and known element types. Discover labeled tuples for readability.
Tuples & labeled tuples is a free TypeScript Academy lesson on CoddyKit — lesson 2 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the TypeScript Academy learning path, one of 3 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Intro
Goal: Learn how tuples differ from arrays. They have fixed length and element types, and can be labeled for clarity.
Simple tuple
A tuple defines specific element types at each position, unlike arrays where all elements share a type.
let point: [number, number] = [10, 20];
console.log(point[0], point[1]);Tuple length
Tuples enforce fixed length. Assigning more or fewer elements causes errors.
let coords: [number, number] = [5, 6];
// coords = [5, 6, 7]; // Error: too many elementsMixed types tuple
Tuples can hold different types in specific positions, like an ID, name, and active flag.
let user: [number, string, boolean] = [1, "Ada", true];Labeled tuple
Labeled tuples make positions clearer, improving readability in function signatures and APIs.
type Point = [x: number, y: number];
const p: Point = [3, 4];Guidelines
Guidelines:
- Use tuples for fixed-structure data.
- Prefer labels when meaning matters.
- Stick to arrays for variable-length collections.
Tuple check
Quick check: What is a key feature of tuples compared to arrays?
Recap
Recap: Tuples enforce position-based types and lengths. Labeled tuples improve clarity. Arrays stay flexible, tuples give structure.
Frequently asked questions
Is the “Tuples & labeled tuples” lesson free?
Yes — the full text of “Tuples & labeled tuples” is free to read here on the web, and the TypeScript Academy course includes 3 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the TypeScript Academy course, upgrade to CoddyKit PRO.
What will I learn in “Tuples & labeled tuples”?
Learn about tuples: arrays with fixed length and known element types. Discover labeled tuples for readability. You practise TypeScript Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start TypeScript Academy?
No prior experience is required. TypeScript Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 3, so you can start here or from the beginning and move at your own pace.
How long does the “Tuples & labeled tuples” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this TypeScript Academy lesson?
Yes. Every TypeScript Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Arrays & ReadonlyArray
- Tuples & labeled tuples
- Enums vs const enum vs union-literal alternatives