Apa iku generics lan sepira pentes gunane?

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**Generics** ndadekake samangsa nulis kode sing bisa dienggo maneh, parameterized dening tipe — "tipe variabel" sing diisiin nalika kode dienggo. Generics menehi samangsa ngenggo maneh **tanpa ilang type safety** (alternatif, `any`, ilang). ```ts // Without generics you'd choose between repetition or `any`: function firstAny(arr: any[]): any { return arr[0]; } // loses the element type // With a generic, the type flows through: function first(arr: T[]): T { return arr[0]; } const n = first([1, 2, 3]); // T inferred as number → n: number const s = first(["a", "b"]); // T inferred as string → s: string ``` `T` minangka placeholder; TypeScript **ngenali** saka argument, mula return type presisi — `first([1,2])` menehi `number`, dudu `any`. ## Tipe generics lan kelas ```ts interface ApiResponse { data: T; status: number; } const res: ApiResponse = await getUser(); // res.data is User class Box { constructor(private value: T) {} get(): T { return this.value; } } const box = new Box(123); // Box ``` ## Pirang tipe param ```ts function pair(k: K, v: V): [K, V] { return [k, v]; } pair("id", 42); // [string, number] ``` ## Sepira pentinge Generics nduweni kira-kira saben abstraksi sing bisa dienggo maneh ing TypeScript: `Array`, `Promise`, `Map`, `useState` React, utilitas data-fetching, lan koleksi. Generics ndadekake siji implementasi bisa dienggo kanggo pirang tipe, tetep njaga informasi tipe lengkap saka wiwitan nganti pungkasan — hubungan antarane tipe input lan output dijaga, ora dihapus.