Environment setup (Node, Watchman, Xcode, Android Studio) in React Native - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Node.js used for in React Native development?

Node.js runs JavaScript code outside the browser and is used to run the React Native development server and build tools.

beginner

Why do we install Watchman when setting up React Native on macOS?

Watchman watches for file changes and helps speed up the development process by efficiently detecting code updates.

beginner

What role does Xcode play in React Native development?

Xcode is Apple's IDE used to build and run React Native apps on iOS devices and simulators.

beginner

Why do you need Android Studio for React Native development?

Android Studio provides the Android SDK and emulator to build and test React Native apps on Android devices.

intermediate

What is the purpose of setting environment variables during React Native setup?

Environment variables tell your system where to find tools like Node, Android SDK, and Java, so builds and commands work correctly.

Which tool helps React Native detect file changes quickly on macOS?

A Node.js

B Xcode

C Watchman

D Android Studio

Watchman watches for file changes and improves development speed by detecting updates efficiently.

What is the main use of Xcode in React Native development?

A Building and running iOS apps

B Running Android emulators

C Managing Node.js packages

D Watching file changes

Xcode is used to build and run React Native apps on iOS devices and simulators.

Which software provides the Android SDK needed for React Native Android builds?

A Watchman

B Android Studio

C Node.js

D Xcode

Android Studio includes the Android SDK and emulator required for Android app development.

Why is Node.js important for React Native development?

A It watches file changes

B It compiles Java code

C It manages iOS simulators

D It runs the React Native development server

Node.js runs the development server that bundles JavaScript code for React Native apps.

What must you configure to let your system find Android SDK tools?

A Set environment variables

B Install Watchman

C Install Xcode

D Run Node.js server

Setting environment variables like ANDROID_HOME tells your system where Android SDK tools are located.

Explain the purpose of each main tool (Node.js, Watchman, Xcode, Android Studio) in setting up a React Native environment.

Think about what each tool helps you do during app development.

Describe the steps to prepare your computer for React Native development on both iOS and Android.

Consider the tools and configurations needed for both platforms.

Practice

1. Which tool do you need to install to run JavaScript code outside a web browser when setting up React Native?

easy

A. Xcode

B. Watchman

C. Android Studio

D. Node.js

Solution

1. Step 1: Understand the role of Node.js

   Node.js allows running JavaScript code on your computer, outside the browser, which is essential for React Native development.

2. Step 2: Identify other tools' purposes

   Watchman watches file changes, Xcode is for iOS apps, and Android Studio is for Android apps, but none run JavaScript directly.

3. Final Answer:

   Node.js -> Option D

4. Quick Check:

   JavaScript runtime = Node.js [OK]

Hint: Node.js runs JavaScript outside browsers [OK]

Common Mistakes:

• Confusing Watchman as JavaScript runtime
• Thinking Xcode runs JavaScript
• Assuming Android Studio runs JavaScript

2. Which command correctly checks the installed version of Watchman on macOS?

easy

A. xcodebuild -version

B. node -v

C. watchman --version

D. android-studio --version

Solution

1. Step 1: Identify the command for Watchman version

   The command to check Watchman version is watchman --version.

2. Step 2: Recognize other commands check different tools

   node -v checks Node.js, xcodebuild -version checks Xcode, and android-studio --version is not a valid command.

3. Final Answer:

   watchman --version -> Option C

4. Quick Check:

   Watchman version command = watchman --version [OK]

Hint: Watchman version uses watchman --version [OK]

Common Mistakes:

• Using node -v for Watchman
• Trying android-studio --version (invalid)
• Using xcodebuild -version for Watchman

3. What will be the output of the command xcodebuild -version after installing Xcode correctly?

medium

A. watchman version 4.9.0

B. Xcode 14.3
Build version 14E222b

C. Node.js v18.12.1

D. Android Studio 2022.1.1

Solution

1. Step 1: Understand the command output

   The command xcodebuild -version outputs the Xcode version and build number.

2. Step 2: Match output to correct tool

   Output mentioning "Xcode" and build version matches Xcode, others show versions of different tools.

3. Final Answer:

   Xcode 14.3\nBuild version 14E222b -> Option B

4. Quick Check:

   Xcode version command output = Xcode 14.3 Build version 14E222b [OK]

Hint: Xcode version shows 'Xcode' and build number [OK]

Common Mistakes:

• Confusing Node.js version output with Xcode
• Mixing Watchman output with Xcode
• Expecting Android Studio output from xcodebuild

4. You run node -v but get an error saying command not found. What is the most likely cause?

medium

A. Node.js is not installed or not added to PATH

B. Watchman is not running

C. Xcode is not installed

D. Android Studio is outdated

Solution

1. Step 1: Analyze the error message

   "command not found" means the system cannot find the node command, usually because Node.js is missing or PATH is incorrect.

2. Step 2: Eliminate unrelated causes

   Watchman, Xcode, and Android Studio do not affect the node command availability.

3. Final Answer:

   Node.js is not installed or not added to PATH -> Option A

4. Quick Check:

   Command not found = missing Node.js or PATH issue [OK]

Hint: Command not found means missing install or PATH error [OK]

Common Mistakes:

• Assuming Watchman affects node command
• Thinking Xcode installation affects node
• Blaming Android Studio for node errors

5. You want to develop a React Native app for both iOS and Android. Which combination of tools must you install and verify?

hard

A. Node.js, Watchman, Xcode, Android Studio

B. Node.js, Xcode only

C. Watchman, Android Studio only

D. Xcode and Android Studio only

Solution

1. Step 1: Identify tools needed for iOS and Android

   Xcode is required for iOS development, Android Studio for Android, Node.js to run JavaScript, and Watchman to watch file changes on macOS.

2. Step 2: Confirm all tools for full setup

   To develop for both platforms, all four tools must be installed and verified.

3. Final Answer:

   Node.js, Watchman, Xcode, Android Studio -> Option A

4. Quick Check:

   All tools for iOS and Android = Node.js, Watchman, Xcode, Android Studio [OK]

Hint: All four tools needed for full React Native setup [OK]

Common Mistakes:

• Skipping Watchman on macOS
• Installing only Xcode or Android Studio
• Forgetting Node.js is essential