Expo Go for quick start in React Native - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ ui_behavior

intermediate

What happens when you scan an Expo Go QR code?

You scan a QR code generated by Expo Go for a React Native app. What is the immediate result on your phone?

A Nothing happens because Expo Go requires manual app installation first.

B Your phone opens the app store to download the app permanently.

C The Expo Go app downloads and runs the JavaScript bundle of the app instantly.

D The QR code opens a web page in the browser instead of running the app.

💡 Hint

Think about how Expo Go lets you preview apps without installing them.

Expo Go uses the QR code to fetch the JavaScript bundle from your development server and runs it inside the Expo Go app immediately.

🧠 Conceptual

intermediate

Why use Expo Go for quick start in React Native?

Which of these is the main advantage of using Expo Go when starting a React Native project?

A It automatically publishes your app to the app stores.

B It allows running your app on a device without building a native binary first.

C It replaces the need for writing JavaScript code.

D It requires no internet connection to run your app.

💡 Hint

Think about how Expo Go helps you test your app quickly on real devices.

Expo Go lets you run your React Native app on a phone instantly by loading the JavaScript bundle, skipping the native build step.

❓ lifecycle

advanced

What happens if you close Expo Go while your app is running?

If you close the Expo Go app on your phone while your React Native app is running inside it, what happens to your app?

A The app switches to a web version automatically.

B The app continues running in the background indefinitely.

C The app crashes and restarts automatically.

D The React Native app stops running immediately.

💡 Hint

Consider how mobile apps behave when their container app is closed.

Expo Go hosts your React Native app; closing Expo Go stops the app because it runs inside Expo Go.

❓ navigation

advanced

How to reload your app in Expo Go after code changes?

After editing your React Native code, how do you reload the app in Expo Go to see the changes?

A Shake the device and select 'Reload' from the developer menu.

B Close and reopen Expo Go app completely.

C Scan the QR code again to reload the app.

D Restart your computer to refresh the app.

💡 Hint

Expo Go has a developer menu accessible by a gesture.

Shaking the device opens the Expo developer menu where you can reload the app to see code changes.

📝 Syntax

expert

What error occurs if you run Expo Go without starting the development server?

You open Expo Go and scan the QR code, but the development server is not running. What error will Expo Go show?

A "Could not connect to development server" error message.

B "Syntax error in JavaScript code" message.

C "App installed successfully" message with blank screen.

D "App is running offline" message with full functionality.

💡 Hint

Think about what Expo Go needs to load your app code.

Expo Go needs the development server to serve the JavaScript bundle; if it's off, it shows a connection error.