Typowane tablice: T[] i Array<T>

Wprowadzenie

Składnia T[]

const numbers: number[] = [1, 2, 3];
const names: string[] = ['Alice', 'Bob'];
const flags: boolean[] = [true, false, true];

Składnia generyczna Array<T>

const scores: Array<number> = [95, 87, 73];
const tags: Array<string> = ['typescript', 'beginner'];

Błędy typów w tablicach

const ids: number[] = [1, 2, 3];
// ids.push('four'); // Error: Argument of type 'string' is not assignable to 'number'

Wywnioskowane typy tablic

const nums = [1, 2, 3];    // inferred: number[]
const mixed = [1, 'hi'];   // inferred: (string | number)[]
const empty: string[] = []; // must annotate

Tablice obiektów

interface User { id: number; name: string; }
const users: User[] = [
  { id: 1, name: 'Alice' },
  { id: 2, name: 'Bob' },
];

Typowanie typowych metod tablic

const nums: number[] = [1, 2, 3, 4];
const doubled: number[] = nums.map(n => n * 2);
const evens: number[] = nums.filter(n => n % 2 === 0);

Tablice zagnieżdżone

const matrix: number[][] = [
  [1, 2, 3],
  [4, 5, 6],
];

Tablice unii

const mixed: (string | number)[] = ['Alice', 1, 'Bob', 2];

Destrukturyzacja tablic z typami

const coords: number[] = [10, 20];
const [x, y] = coords; // x: number, y: number

Wybór między T[] a Array<T>

Szybkie sprawdzenie

Podsumowanie