Flutter vs React Native comparison - UI Rendering Compared

Component - Flutter vs React Native comparison

This UI component compares Flutter and React Native by showing two simple buttons labeled "Flutter" and "React Native". When you tap a button, it highlights to show selection, helping you understand how each framework handles UI and interaction.

Widget Tree

Scaffold
├── AppBar
│   └── Text("Flutter vs React Native")
└── Column
    ├── Padding
    │   └── Text("Choose your framework:")
    └── Row
        ├── ElevatedButton("Flutter")
        └── ElevatedButton("React Native")

The Scaffold provides the basic screen structure with an AppBar at the top showing the title. Below, a Column arranges a prompt text and a Row with two buttons side by side. Each button represents one framework for comparison.

Render Trace - 7 Steps

Step 1: Scaffold

Step 2: AppBar

Step 3: Column

Step 4: Text

Step 5: Row

Step 6: ElevatedButton("Flutter")

Step 7: ElevatedButton("React Native")

State Change - Re-render

Trigger:User taps either the "Flutter" or "React Native" button

Before

No framework selected, both buttons have default style

→

After

Tapped button is highlighted, other button returns to default style

Re-renders:The Row containing both buttons re-renders to update button styles

UI Quiz - 3 Questions

What widget arranges the two framework buttons side by side?

A Column

B Stack

C Row

D ListView

Key Insight

Using simple layout widgets like Column and Row helps organize UI elements clearly. Stateful widgets let you update the UI when users interact, such as highlighting a selected button. This example shows how Flutter builds UI with a clear widget tree and updates only parts that change.

Practice

1. Which programming language does Flutter primarily use for app development?

easy

A. Kotlin

B. JavaScript

C. Swift

D. Dart

Solution

1. Step 1: Identify Flutter's language

   Flutter uses Dart as its main programming language for building apps.

2. Step 2: Compare with other options

   JavaScript is used by React Native, Kotlin and Swift are for native Android and iOS development respectively.

3. Final Answer:

   Dart -> Option D

4. Quick Check:

   Flutter = Dart [OK]

Hint: Flutter always uses Dart language for coding apps [OK]

Common Mistakes:

• Confusing Flutter's Dart with React Native's JavaScript
• Thinking Flutter uses native languages like Kotlin or Swift

2. Which of the following is the correct way to create a simple button in React Native?

easy

A. alert('Hello')}>Click me

B. ElevatedButton(onPressed: () => print('Hello'), child: Text('Click me'))

C. alert('Hello')} />

D. Button('Click me', onPress: () => alert('Hello'))

Solution

1. Step 1: Recognize React Native button syntax

   React Native uses JSX syntax with <Button> component and props like title and onPress.

2. Step 2: Eliminate other options

   ElevatedButton(onPressed: () => print('Hello'), child: Text('Click me')) is Flutter syntax, C is HTML, D is invalid syntax.

3. Final Answer:

   <Button title='Click me' onPress={() => alert('Hello')} /> -> Option C

4. Quick Check:

   React Native button uses <Button title=... onPress=... /> [OK]

Hint: React Native buttons use JSX with title and onPress props [OK]

Common Mistakes:

• Using Flutter button syntax in React Native
• Confusing HTML button with React Native
• Incorrect event handler names

3. What is a key difference in UI rendering between Flutter and React Native?

medium

A. Flutter uses native UI components; React Native uses custom widgets.

B. Flutter uses a single rendering engine with widgets; React Native uses native platform components.

C. Both Flutter and React Native use native UI components directly.

D. React Native uses a custom rendering engine; Flutter uses native components.

Solution

1. Step 1: Understand Flutter's rendering

   Flutter draws UI using its own rendering engine and widgets, not native components.

2. Step 2: Understand React Native's rendering

   React Native uses native platform UI components for rendering.

3. Final Answer:

   Flutter uses a single rendering engine with widgets; React Native uses native platform components. -> Option B

4. Quick Check:

   Flutter = custom engine; React Native = native components [OK]

Hint: Flutter draws widgets itself; React Native uses native UI elements [OK]

Common Mistakes:

• Thinking Flutter uses native UI components
• Confusing React Native with Flutter rendering
• Assuming both use same rendering method

4. You wrote this Flutter code but the app crashes on start:

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

What is the likely cause?

medium

A. No error; code runs fine

B. Text widget must be inside a Center widget in Scaffold body

C. StatelessWidget requires a const constructor

D. Missing a MaterialApp widget around Scaffold

Solution

1. Step 1: Analyze Scaffold body usage

   Scaffold body can accept a Text widget directly; it does not cause a crash.

2. Step 2: Confirm no crash

   The code runs fine as is; wrapping Text in Center is optional for layout but not required to prevent crash.

3. Final Answer:

   No error; code runs fine -> Option A

4. Quick Check:

   Scaffold body accepts Text widget directly [OK]

Hint: Text widget can be used directly in Scaffold body without crash [OK]

Common Mistakes:

• Assuming MaterialApp is missing
• Thinking StatelessWidget needs const constructor
• Incorrectly assuming Text alone causes crash

5. You want your app to look exactly the same on Android and iOS with smooth animations and consistent UI. Which framework is better suited and why?

hard

A. Flutter, because it uses its own rendering engine and widgets for consistent UI

B. Flutter, because it uses JavaScript for faster development

C. React Native, because it compiles to native code for performance

D. React Native, because it uses native components for each platform

Solution

1. Step 1: Understand UI consistency needs

   To have identical UI on Android and iOS, a single rendering engine controlling UI is best.

2. Step 2: Match framework to need

   Flutter uses its own rendering engine and widgets, ensuring consistent UI and smooth animations across platforms.

3. Step 3: Eliminate wrong options

   React Native uses native components, so UI differs per platform; Flutter does not use JavaScript.

4. Final Answer:

   Flutter, because it uses its own rendering engine and widgets for consistent UI -> Option A

5. Quick Check:

   Consistent UI = Flutter's custom rendering [OK]

Hint: For identical UI on all platforms, choose Flutter [OK]

Common Mistakes:

• Choosing React Native for consistent UI
• Thinking Flutter uses JavaScript
• Confusing native components with consistent UI