# Dasar-Dasar JavaScript (React Native)

> Variabel (let/const/var), tipe, closures, this, arrow functions, destructuring, spread/rest

- 25 pertanyaan wawancara
- Junior
- [Pertanyaan Wawancara: React Native](https://sharpskill.dev/id/technologies/react-native/pertanyaan-wawancara.md)

## 1. Apa perbedaan utama antara let dan var di JavaScript?

**Jawaban**

let memiliki block scope sedangkan var memiliki function scope. Ini berarti variabel yang dideklarasikan dengan let hanya dapat diakses di dalam blok tempatnya didefinisikan (di antara kurung kurawal), sedangkan var dapat diakses di seluruh fungsi. Perbedaan ini sangat penting untuk menghindari bug yang terkait dengan hoisting dan variabel yang bocor keluar dari konteks yang dimaksudkan.

## 2. Apa yang terjadi saat mengakses variabel let sebelum dideklarasikan?

**Jawaban**

ReferenceError dilemparkan karena variabel berada di Temporal Dead Zone (TDZ). Tidak seperti var yang di-hoisting dengan nilai undefined, variabel let di-hoisting tetapi tetap tidak dapat diakses hingga dideklarasikan. Zona mati sementara ini membantu mendeteksi kesalahan pemrograman di mana variabel digunakan sebelum didefinisikan.

## 3. Apa karakteristik utama const di JavaScript?

**Jawaban**

const mencegah penugasan ulang referensi tetapi tidak mencegah mutasi konten. Untuk tipe primitif, ini berarti nilainya tidak dapat berubah. Untuk objek dan array, referensinya tetap sama tetapi properti atau elemen dapat dimodifikasi. Menggunakan const secara default adalah praktik yang baik karena mengekspresikan niat untuk tidak menugaskan ulang variabel.

## 22 pertanyaan lagi tersedia

- Apa saja tipe primitif di JavaScript?
- Apa hasil dari typeof null di JavaScript?

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## Topik wawancara React Native lainnya

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