Quiz for Building the React App

Q1: What command is used to create a production build of a React app?

A. A. npm run build B. B. npm start C. C. npm test D. D. npm install

Q2: Where is the build output stored by default?

A. A. build/ directory B. B. src/ directory C. C. public/ directory D. D. dist/ directory

Q3: Which of these files contains the entry point for React in the build?

A. A. index.html B. B. package.json C. C. app.js D. D. main.css

Q4: What type of files are generated in the build folder?

A. A. Minified JavaScript, CSS, and static assets B. B. Unminified JavaScript C. C. Source code files D. D. JSON config files

Q5: How can environment variables be injected during the build?

A. A. Using .env files with REACT_APP_ prefix B. B. Directly in source code C. C. Through package.json D. D. Using Webpack config

Q6: Which bundler does Create React App use by default?

A. A. Webpack B. B. Rollup C. C. Parcel D. D. Browserify

Q7: What does "npm start" do in a React app?

A. A. Starts a development server B. B. Creates a production build C. C. Runs tests D. D. Installs dependencies

Q8: Can the build output be deployed to any static file server?

A. A. Yes, because the build output is static B. B. No, it needs a Node.js server C. C. No, it requires a React server D. D. Only to AWS

Q9: Which folder contains the public assets that are copied as-is during build?

A. A. public/ B. B. src/ C. C. build/ D. D. assets/

Q10: How can you serve the React production build locally to test?

A. A. Using a static server like serve B. B. Using npm start C. C. Opening index.html directly in browser D. D. Using React Developer Tools

Q11: What is the typical size impact of minification in React build?

A. A. Reduces size significantly by removing whitespace and shortening variables B. B. Increases size due to bundling C. C. Has no effect on size D. D. Only affects CSS

Q12: Which file typically contains the build scripts in a React project?

A. A. package.json B. B. index.html C. C. README.md D. D. webpack.config.js

Q13: What is a common reason to eject a CRA app?

A. A. To customize the Webpack config B. B. To add tests C. C. To run the development server D. D. To upgrade React version

Q14: How does the build process handle source maps?

A. A. Generates source maps for debugging B. B. Removes all source maps C. C. Source maps are included inline D. D. Source maps are not supported

Q15: Which command cleans the build folder before creating a new build?

A. A. npm run build (automatically cleans) B. B. npm clean C. C. npm build D. D. npm clear

Q16: Is React build output server-side rendered?

A. A. No, it is client-side rendered by default B. B. Yes, always C. C. Yes, if configured D. D. No, unless using Next.js

Q17: How can you enable gzip compression for React build files?

A. A. Configure the web server (e.g., Nginx, Apache) B. B. During npm run build C. C. By using a React plugin D. D. Compression is automatic

Q18: Which environment variable controls the public URL of the app?

A. A. PUBLIC_URL B. B. REACT_APP_URL C. C. APP_URL D. D. BASE_URL

Q19: What happens if you deploy a React build on a server without redirecting to index.html?

A. A. React Router may not work properly B. B. The app will crash C. C. The build fails D. D. The app loads faster

Q20: How do you configure a React app to be served from a subdirectory?

A. A. Set "homepage" in package.json and use PUBLIC_URL B. B. Modify index.html directly C. C. Change src folder location D. D. Use npm run serve