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. This is 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, and your progress syncs across the web and the CoddyKit app. The TypeScript Academy course includes 3 lessons in total.
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.
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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. 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. The TypeScript Academy course includes 3 lessons in total.
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, so you can start here or from the beginning and move at your own pace. This is lesson 2 of 3.
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