In this section, we will guide you through the process of setting up your development environment for React Native. This involves installing the necessary software and tools to start building React Native applications.

Before we begin, ensure you have the following:

• A computer with either macOS, Windows, or Linux.
• Basic knowledge of JavaScript and command-line operations.

React Native requires Node.js and npm (Node Package Manager). You can download and install them from the official Node.js website.

1. Go to the Node.js download page.
2. Download the LTS (Long Term Support) version.
3. Follow the installation instructions for your operating system.

To verify the installation, open your terminal or command prompt and run:

You should see the version numbers of Node.js and npm.

Watchman is a tool developed by Facebook for watching changes in the filesystem. It is highly recommended for macOS users.

1. Install Homebrew if you haven't already:

   /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
   

2. Install Watchman using Homebrew:

   brew install watchman
   

The React Native CLI is a command-line tool that helps you create, build, and run React Native projects.

1. Install the React Native CLI globally:

   npm install -g react-native-cli
   

Install Android Studio

1. Download and install Android Studio.
2. During installation, ensure the boxes for "Android SDK," "Android SDK Platform," and "Android Virtual Device" are checked.

Configure the Android SDK

1. Open Android Studio.
2. Go to Preferences > Appearance & Behavior > System Settings > Android SDK.
3. Select the SDK Platforms tab and ensure Show Package Details is checked.
4. Install the following packages:
   • Android SDK Platform 29
   • Intel x86 Atom_64 System Image or Google APIs Intel x86 Atom System Image
5. Select the SDK Tools tab and ensure Show Package Details is checked.
6. Install the following:
   • Android SDK Build-Tools 29.0.2
   • Android Emulator
   • Android SDK Platform-Tools
   • Android SDK Tools

Set Up Environment Variables

1. Add the following lines to your ~/.bash_profile or ~/.zshrc (depending on your shell):

   export ANDROID_HOME=$HOME/Library/Android/sdk
   export PATH=$PATH:$ANDROID_HOME/emulator
   export PATH=$PATH:$ANDROID_HOME/tools
   export PATH=$PATH:$ANDROID_HOME/tools/bin
   export PATH=$PATH:$ANDROID_HOME/platform-tools
   

2. Apply the changes:

   source ~/.bash_profile
   

Install Xcode

1. Download and install Xcode from the Mac App Store.
2. Open Xcode and install any additional components if prompted.

Install Xcode Command Line Tools

1. Open your terminal and run:

   xcode-select --install
   

Now that your environment is set up, let's create a new React Native project to ensure everything is working correctly.

1. Open your terminal and run:

   npx react-native init MyFirstApp
   

2. Navigate to the project directory:

   cd MyFirstApp
   

On Android

1. Start an Android emulator from Android Studio or connect an Android device via USB.
2. Run the following command in your project directory:

   npx react-native run-android
   

On iOS (macOS only)

1. Open the iOS project in Xcode:

   npx react-native run-ios
   

Congratulations! You have successfully set up your development environment for React Native. You are now ready to start building your first React Native application. In the next section, we will create a simple "Hello World" app to get you familiar with the basics of React Native.