Hari 5: Enum & Literal Types

Enum — Kumpulan Konstanta Bernama

// Numeric enum (default)
enum Arah {
    Utara,   // 0
    Selatan, // 1
    Timur,   // 2
    Barat,   // 3
}
console.log(Arah.Utara);  // 0
console.log(Arah[0]);     // "Utara"

// String enum (lebih aman untuk debugging)
enum Status {
    Aktif    = "ACTIVE",
    NonAktif = "INACTIVE",
    Pending  = "PENDING",
}
const s: Status = Status.Aktif;
console.log(s); // "ACTIVE"

// Const enum — dihapus saat kompilasi, lebih efisien
const enum Ukuran { XS, S, M, L, XL }

Literal Types

// String literal
type Tema = "light" | "dark" | "system";
let tema: Tema = "dark";

// Number literal
type Dadu = 1 | 2 | 3 | 4 | 5 | 6;
let hasil: Dadu = 4;

// Template literal type (TS 4.1+)
type Arah2 = "north" | "south" | "east" | "west";
type KoordinatLabel = `${number},${number}`;
type EventName = `on${Capitalize}`;