Profiling with Flipper in React Native - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ ui_behavior

intermediate

Identify the correct Flipper plugin for React Native performance profiling

Which Flipper plugin helps you monitor React Native app performance by showing CPU usage, memory, and network requests in real time?

A React DevTools

B React Native Performance

C Network Inspector

D Layout Inspector

💡 Hint

Look for the plugin that focuses on performance metrics like CPU and memory.

The React Native Performance plugin in Flipper is designed to profile app performance, showing CPU, memory, and network usage live.

🧠 Conceptual

intermediate

Understanding Flipper's role in React Native development

What is the main purpose of using Flipper in React Native app development?

A To debug and profile React Native apps with visual tools

B To write React Native code faster

C To deploy React Native apps to app stores

D To convert React Native apps to native Android apps

💡 Hint

Think about tools that help find and fix problems during development.

Flipper is a debugging and profiling platform that provides visual tools to inspect React Native apps during development.

❓ lifecycle

advanced

When to enable Flipper in React Native apps

At which stage of React Native app development is it best to enable Flipper for profiling?

A Only in production builds to monitor live users

B Only during initial app setup before writing code

C During development and debugging phases to optimize performance

D After app release to collect crash reports

💡 Hint

Profiling tools help improve app performance before release.

Flipper is mainly used during development and debugging to profile and optimize app performance before releasing to users.

🔧 Debug

advanced

Diagnosing a Flipper connection issue

You installed Flipper and the React Native Performance plugin, but your app does not show up in Flipper. What is the most likely cause?

A The React Native app was built without Flipper enabled in the debug configuration

B Flipper requires a physical device; emulators are not supported

C Flipper only works with iOS apps, not Android

D You must restart the app store to connect Flipper

💡 Hint

Check your app build settings for Flipper integration.

If Flipper does not detect the app, it is often because the app was built without enabling Flipper in the debug build configuration.

📝 Syntax

expert

Correct React Native Flipper setup code snippet

Which code snippet correctly enables Flipper in a React Native Android app's MainApplication.java file?

React Native

public class MainApplication extends Application implements ReactApplication {
  private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) {
    @Override
    public boolean getUseDeveloperSupport() {
      return BuildConfig.DEBUG;
    }

    @Override
    protected List<ReactPackage> getPackages() {
      return Arrays.<ReactPackage>asList(
        new MainReactPackage(),
        // Add Flipper package here
      );
    }

    @Override
    protected String getJSMainModuleName() {
      return "index";
    }
  };

  @Override
  public ReactNativeHost getReactNativeHost() {
    return mReactNativeHost;
  }
}

A Add new FlipperPackage() inside MainApplication constructor

B Add new FlipperPackage() inside getUseDeveloperSupport() method

C Add new FlipperPackage() inside getJSMainModuleName() method

D Add new FlipperPackage() inside getPackages() list

💡 Hint

Flipper packages go inside the list of React packages.

Flipper integration requires adding the FlipperPackage to the list returned by getPackages() in MainApplication.java.