React Native vs Flutter comparison - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Which framework uses Dart language?

Both React Native and Flutter are popular for mobile app development. Which one uses Dart as its programming language?

A Neither React Native nor Flutter

B Both React Native and Flutter

C React Native

D Flutter

💡 Hint

Think about which framework was created by Google and uses a less common language.

Flutter uses Dart language, which was developed by Google. React Native uses JavaScript.

❓ ui_behavior

intermediate

Which framework uses native UI components by default?

React Native and Flutter both create mobile apps. Which one uses native UI components of the platform by default?

A React Native uses native UI components by default

B Flutter uses native UI components by default

C Both use native UI components by default

D Neither uses native UI components by default

💡 Hint

One framework renders its own UI widgets instead of using platform widgets.

React Native uses native UI components, while Flutter renders its own widgets.

❓ lifecycle

advanced

How does hot reload differ between React Native and Flutter?

Both React Native and Flutter support hot reload. Which statement best describes the difference in their hot reload behavior?

A Flutter's hot reload updates UI instantly without losing state; React Native reloads entire app losing state

B React Native's hot reload updates UI instantly without losing state; Flutter reloads entire app losing state

C Both frameworks reload the entire app losing state during hot reload

D Both frameworks update UI instantly without losing state during hot reload

💡 Hint

Consider which framework is known for very fast UI updates preserving app state.

Flutter's hot reload is faster and preserves app state better than React Native's.

❓ navigation

advanced

Which framework requires third-party libraries for navigation?

In mobile app development, navigation between screens is essential. Which framework requires third-party libraries for navigation?

A Neither React Native nor Flutter support navigation

B React Native requires third-party libraries for navigation

C Both React Native and Flutter have built-in navigation without third-party libraries

D Flutter requires third-party libraries for navigation

💡 Hint

One framework has a built-in navigation system, the other relies on external packages.

React Native needs libraries like React Navigation; Flutter has built-in Navigator widget.

🔧 Debug

expert

What error occurs if you try to use a Flutter widget in React Native code?

Imagine you accidentally try to use a Flutter widget like Container inside React Native JavaScript code. What error will you get?

A SyntaxError: Unexpected token <

B TypeError: Container is not a function

C ReferenceError: Container is not defined

D No error, it works fine

💡 Hint

Think about what happens when you use an unknown component in JavaScript.

React Native JavaScript will throw ReferenceError because Container is not defined in its scope.

Practice

1. Which language does React Native primarily use for building apps?

easy

A. Kotlin

B. Dart

C. JavaScript and JSX

D. Swift

Solution

1. Step 1: Identify React Native's programming language

   React Native uses JavaScript along with JSX syntax to build UI components.

2. Step 2: Compare with other options

   Dart is used by Flutter, Swift and Kotlin are native languages for iOS and Android respectively.

3. Final Answer:

   JavaScript and JSX -> Option C

4. Quick Check:

   React Native = JavaScript and JSX [OK]

Hint: React Native uses JavaScript, Flutter uses Dart [OK]

Common Mistakes:

• Confusing Flutter's Dart with React Native's JavaScript
• Thinking React Native uses native languages like Swift
• Assuming JSX is a separate language

2. Which of the following is the correct way to create a button in Flutter?

easy

A. <TouchableOpacity>Click</TouchableOpacity>

B. Button(title: 'Click')

C. <Button title='Click' />

D. ElevatedButton(onPressed: () {}, child: Text('Click'))

Solution

1. Step 1: Understand Flutter widget syntax

   Flutter uses Dart and widgets like ElevatedButton with named parameters.

2. Step 2: Identify correct button syntax

   ElevatedButton(onPressed: () {}, child: Text('Click')) uses ElevatedButton with onPressed callback and child Text widget, which is correct.

3. Final Answer:

   ElevatedButton(onPressed: () {}, child: Text('Click')) -> Option D

4. Quick Check:

   Flutter buttons use widgets with callbacks [OK]

Hint: Flutter buttons use widgets with onPressed callback [OK]

Common Mistakes:

• Using JSX or HTML-like syntax in Flutter
• Omitting onPressed callback in Flutter button
• Confusing React Native TouchableOpacity with Flutter widgets

3. What will be the output of this React Native code snippet?

import React from 'react';
import { Text, View } from 'react-native';

export default function App() {
  return (
    
      Hello from React Native!
    
  );
}

medium

A. A screen displaying the text: Hello from React Native!

B. A blank screen with no text

C. Syntax error due to missing import

D. App crashes on launch

Solution

1. Step 1: Analyze the React Native component

   The component returns a View containing a Text element with the string 'Hello from React Native!'.

2. Step 2: Understand rendering behavior

   React Native renders the View and Text properly, so the text will appear on screen.

3. Final Answer:

   A screen displaying the text: Hello from React Native! -> Option A

4. Quick Check:

   React Native renders JSX as UI [OK]

Hint: React Native JSX renders UI elements directly [OK]

Common Mistakes:

• Thinking View or Text won't render without styles
• Assuming missing styles cause crash
• Confusing React Native with web React

4. Identify the error in this Flutter code snippet:

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Text('Hello Flutter'),
      ),
    );
  }
}

medium

A. Missing @override annotation before build method

B. build method should return a Widget but returns void

C. Missing const keyword before MaterialApp

D. build method lacks override keyword and is missing @override

Solution

1. Step 1: Check Flutter build method requirements

   In Flutter, the build method should have the @override annotation to indicate it overrides a superclass method.

2. Step 2: Identify missing annotation

   The code lacks the @override annotation before the build method, which is a recommended practice to avoid errors.

3. Final Answer:

   Missing @override annotation before build method -> Option A

4. Quick Check:

   Flutter build methods need @override annotation [OK]

Hint: Always add @override before build in Flutter widgets [OK]

Common Mistakes:

• Ignoring missing @override annotation warnings
• Confusing const keyword necessity
• Thinking build returns void instead of Widget

5. You want to build a mobile app with highly customized UI components and smooth animations. Which framework is generally better suited for this need?

hard

A. React Native, because it uses native UI components by default

B. Flutter, because it offers more control over custom UI and animations

C. React Native, because it compiles to native ARM code

D. Flutter, because it uses JavaScript and JSX for UI

Solution

1. Step 1: Understand UI customization capabilities

   Flutter renders its own widgets and provides extensive control over UI and animations, allowing highly customized designs.

2. Step 2: Compare with React Native's approach

   React Native uses native UI components, which can limit deep customization and complex animations compared to Flutter.

3. Final Answer:

   Flutter, because it offers more control over custom UI and animations -> Option B

4. Quick Check:

   Flutter = better custom UI and animations [OK]

Hint: Flutter excels in custom UI and animations [OK]

Common Mistakes:

• Assuming React Native compiles to native ARM code
• Confusing Flutter's language as JavaScript
• Thinking native UI always means better customization