(Code Examination)

Examine the following Flutter code for navigating between pages. Identify any issues and suggest improvements for managing data passed between pages.

Navigator.push(

  context,

  MaterialPageRoute(

    builder: (context) => SecondPage(data: 'Hello, Second Page!'),

  ),

);

// In SecondPage:

Navigator.pop(context, 'Hello, First Page!');

(Code Examination)

Evaluate the correctness of the following Flutter code for saving a user's details to Firestore. Does it handle error cases properly? Suggest improvements.

Future<void> saveUserDetails(Map<String, dynamic> userDetails) async {

  final userCollection = FirebaseFirestore.instance.collection('users');

  try {

    await userCollection.doc(userDetails['id']).set(userDetails);

    print('User details saved successfully');

  } catch (e) {

    print('Error saving user details: $e');

  }

}

(Create)

Create a Flutter application that uses a ListView to display a list of items fetched from a REST API. Include a RefreshIndicator to reload the list.

(Design)

Design a Flutter interface with a TextField for entering a username and a Text widget to display the entered username in real-time below it.

(Create)

Create a Flutter UI that displays a map with the current user's location. Include a button that, when clicked, re-centers the map on the user's updated location.

Given the following code, identify the day that will be printed if day is 5.

void main() {

  int day = 5;

  switch (day) {

    case 1:

      print("Monday");

      break;

    case 2:

      print("Tuesday");

      break;

    case 3:

      print("Wednesday");

      break;

    case 4:

      print("Thursday");

      break;

    case 5:

      print("Friday");

      break;

    default:

      print("Invalid day");

  }

}

(Code Examination)

Analyze the following Flutter code snippet. What happens if the onPressed method is invoked multiple times? Is there a risk of overwriting data?

ElevatedButton(

  onPressed: () async {

    final file = File('/storage/emulated/0/notes.txt');

    await file.writeAsString('This is a note.');

  },

  child: Text('Save Note'),

);

Write a  function that calculates the sum of all even numbers in a list.

(Create)

Design a Flutter application that includes a toggle switch for enabling or disabling Bluetooth. When Bluetooth is enabled, display a list of paired devices.

Create a  function that checks if a number is prime. Return true if it is prime, false otherwise.

  bool isPrime(int num) {

  if (num <= 1) return false;

  for (int i = 2; i <= num ~/ 2; i++) {

    if (num % i == 0) return false;

  }

  return true;

}

Example Usage:

void main() {

  print(isPrime(7)); // Output: true

  print(isPrime(10)); // Output: false

}