Native modules concept in React Native - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a native module in React Native?

A native module is a piece of code written in native platform languages (like Java for Android or Swift/Objective-C for iOS) that can be called from React Native JavaScript code to access platform-specific features.

beginner

Why do we use native modules in React Native apps?

We use native modules to access device features or APIs that are not available in React Native's JavaScript environment, like sensors, camera controls, or advanced system functions.

beginner

Which languages are used to write native modules for Android and iOS?

Android native modules are usually written in Java or Kotlin, while iOS native modules are written in Objective-C or Swift.

intermediate

How does React Native communicate with native modules?

React Native uses a bridge to send messages between JavaScript and native code asynchronously, allowing JavaScript to call native functions and receive results.

beginner

What is a common use case for creating a native module?

A common use case is when you need to use a device feature not supported by React Native, like accessing a custom Bluetooth API or advanced camera controls.

What language is typically used to write native modules for iOS in React Native?

A Java

B JavaScript

C Swift

D Kotlin

Swift (or Objective-C) is used for iOS native modules, while Java or Kotlin is used for Android.

Why might you create a native module in a React Native app?

A To replace React Native entirely

B To improve JavaScript performance

C To write UI components in native code

D To access platform-specific features not available in React Native

Native modules let you access device features or APIs that React Native does not support directly.

How does React Native communicate with native modules?

A Using a bridge asynchronously

B Direct synchronous calls

C Through REST API calls

D By embedding native code in JavaScript

React Native uses a bridge to communicate asynchronously between JavaScript and native code.

Which of these is NOT a typical language for writing native modules?

A Python

B Kotlin

C Objective-C

D Java

Python is not used for native modules in React Native; native modules use platform languages like Java, Kotlin, Objective-C, or Swift.

What is the main benefit of using native modules?

A Faster JavaScript execution

B Access to native device features

C Simpler app design

D No need for native code knowledge

Native modules allow React Native apps to access native device features not available in JavaScript.

Explain what a native module is and why it is important in React Native development.

Think about how JavaScript talks to native code to use device features.

Describe the process of creating and using a native module in a React Native app.

Consider the steps from native code to JavaScript usage.