Why deployment reaches users in Flutter - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to show a simple Flutter app with a text widget.

Flutter

import 'package:flutter/material.dart';

void main() {
  runApp([1]);
}

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

Drag options to blanks, or click blank then click option'

AScaffold()

BMaterialApp()

CMyApp()

DText('Hello')

Attempts:

3 left

💡 Hint

Common Mistakes

Passing MaterialApp() directly to runApp instead of the root widget.

Passing a widget that is not the app root.

The runApp function needs to receive the root widget of the app, which is MyApp().

2fill in blank

medium

Complete the code to navigate from HomeScreen to DetailScreen when a button is pressed.

Flutter

ElevatedButton(
  onPressed: () {
    Navigator.of(context).[1](
      MaterialPageRoute(builder: (context) => DetailScreen()),
    );
  },
  child: Text('Go to Details'),
)

Drag options to blanks, or click blank then click option'

ApopAndPushNamed

Bpop

Creplace

Dpush

Attempts:

3 left

💡 Hint

Common Mistakes

Using pop instead of push, which goes back instead of forward.

Using replace which is not a Navigator method.

Navigator.push is used to move to a new screen by adding it on top of the stack.

3fill in blank

hard

Fix the error in the code to correctly update the UI when a button is pressed.

Flutter

class CounterWidget extends StatefulWidget {
  @override
  _CounterWidgetState createState() => _CounterWidgetState();
}

class _CounterWidgetState extends State<CounterWidget> {
  int count = 0;

  void increment() {
    [1](() {
      count += 1;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Text('Count: $count'),
        ElevatedButton(onPressed: increment, child: Text('Add')),
      ],
    );
  }
}

Drag options to blanks, or click blank then click option'

AsetState

BupdateUI

Crebuild

Drefresh

Attempts:

3 left

💡 Hint

Common Mistakes

Not calling setState, so UI does not update.

Using a non-existent method like updateUI.

In Flutter, setState tells the framework to redraw the widget with updated data.

4fill in blank

hard

Complete the code to create a map of word lengths for words longer than 3 characters.

Flutter

final words = ['apple', 'bat', 'cat', 'doggy'];
final lengths = {for (final word in words) if (word.length [1] 3) word: word.length};

Drag options to blanks, or click blank then click option'

A:

B>

C<

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' instead of ':' in map.

Using '<' instead of '>' for filtering.

The map uses ':' to assign keys to values, and the condition filters words longer than 3.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension filtering positive values and uppercasing keys.

Flutter

final data = {'a': 1, 'b': -2, 'c': 3};
final result = {for (final (k, v) in data.entries) if (v [3] 0) [1]: [2] };

Drag options to blanks, or click blank then click option'

Ak.toUpperCase()

Bv

C>

Dk

Attempts:

3 left

💡 Hint

Common Mistakes

Not uppercasing keys.

Using '<' instead of '>' in condition.

Swapping keys and values.

Keys are uppercased, values kept as is, and only positive values (v > 0) are included.

Practice

1. What is the main purpose of deploying a Flutter app?

easy

A. To write the app's source code

B. To move the app from your computer to users' devices

C. To design the app's user interface

D. To test the app only on your computer

Solution

1. Step 1: Understand deployment meaning

   Deployment means sending your app from your computer to users' devices so they can use it.

2. Step 2: Identify the correct purpose

   Writing code and designing UI happen before deployment, testing can be local only.

3. Final Answer:

   To move the app from your computer to users' devices -> Option B

4. Quick Check:

   Deployment = move app to users [OK]

Hint: Deployment means sending app to users' devices [OK]

Common Mistakes:

• Confusing deployment with coding
• Thinking deployment is only testing
• Believing deployment is UI design

2. Which Flutter command is used to create a release build for deployment?

easy

A. flutter test

B. flutter run

C. flutter build

D. flutter clean

Solution

1. Step 1: Recall Flutter commands

   flutter run runs the app on a device, flutter test runs tests, flutter clean removes build files.

2. Step 2: Identify build command

   flutter build creates a release version ready for deployment to users.

3. Final Answer:

   flutter build -> Option C

4. Quick Check:

   Build = create release app [OK]

Hint: Use flutter build to prepare app for users [OK]

Common Mistakes:

• Using flutter run instead of flutter build
• Confusing flutter test with deployment
• Thinking flutter clean deploys app

3. What happens if you do NOT deploy your Flutter app after building it?

medium

A. Users cannot open or use the app

B. The app runs automatically on all devices

C. The app updates itself on users' devices

D. The app is visible in app stores without deployment

Solution

1. Step 1: Understand deployment effect

   Deployment sends the app to users' devices so they can open and use it.

2. Step 2: Consequence of no deployment

   If you don't deploy, users never get the app on their devices and cannot use it.

3. Final Answer:

   Users cannot open or use the app -> Option A

4. Quick Check:

   No deployment = no user access [OK]

Hint: No deployment means no app on users' devices [OK]

Common Mistakes:

• Assuming app runs without deployment
• Thinking app updates without deployment
• Believing app appears in stores automatically

4. You ran flutter build apk but users still can't install your app. What is a likely mistake?

medium

A. You did not write any Dart code

B. You used flutter run instead of flutter build

C. You did not open the app in an emulator

D. You forgot to run flutter install to send the app to devices

Solution

1. Step 1: Understand build vs install

   flutter build apk creates the app file but does not send it to devices.

2. Step 2: Identify missing step

   flutter install sends the built app to connected devices for installation.

3. Final Answer:

   You forgot to run flutter install to send the app to devices -> Option D

4. Quick Check:

   Build creates app, install sends it [OK]

Hint: Build creates app; install sends it to devices [OK]

Common Mistakes:

• Confusing flutter run with flutter build
• Thinking build installs app automatically
• Ignoring the install step after build

5. You want to deploy your Flutter app to many users via app stores. Which steps must you follow?

hard

A. Build a release version, sign the app, then upload to app stores

B. Run flutter run on your computer only

C. Write code and wait for automatic deployment

D. Only test the app on an emulator

Solution

1. Step 1: Prepare release build

   You must build a release version of your app for users, not just debug or run locally.

2. Step 2: Sign and upload app

   App stores require apps to be signed for security before uploading for distribution.

3. Final Answer:

   Build a release version, sign the app, then upload to app stores -> Option A

4. Quick Check:

   Release build + sign + upload = deployment [OK]

Hint: Release build, sign, then upload to app stores [OK]

Common Mistakes:

• Skipping signing step before upload
• Thinking flutter run deploys app store version
• Expecting automatic deployment without action