Error handling for network calls in Flutter - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to catch exceptions during a network call.

Flutter

try {
  final response = await http.get(Uri.parse('https://api.example.com/data'));
  print(response.body);
} catch ([1]) {
  print('Error occurred');
}

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

AException

Bint

CString

Ddouble

Attempts:

3 left

💡 Hint

Common Mistakes

Using data types like int or String instead of Exception.

Not using a catch block to handle errors.

The catch block catches exceptions of type Exception during network calls.

2fill in blank

medium

Complete the code to check if the HTTP response status code indicates success.

Flutter

if (response.statusCode [1] 200) {
  print('Success');
} else {
  print('Failed');
}

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

A==

B>=

C<=

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using greater than or less than operators instead of equality.

Checking for status codes other than 200 for success.

The status code 200 means the request was successful, so we check if it equals 200.

3fill in blank

hard

Fix the error in the catch block to print the error message.

Flutter

try {
  final response = await http.get(Uri.parse('https://api.example.com/data'));
} catch (e) {
  print([1]);
}

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

Aerror

Be.toString()

Ce.message

Dexception

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to print undefined variables like 'error' or 'exception'.

Using 'e.message' which may not exist on all exceptions.

Using e.toString() converts the error object to a readable string message.

4fill in blank

hard

Fill both blanks to retry the network call only if the status code is 500.

Flutter

if (response.statusCode [1] 500) {
  await Future.delayed(Duration(seconds: [2]));
  // retry logic here
}

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

A==

B3

C<

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong comparison operators.

Not adding a delay before retrying.

We check if status code equals 500 and wait 3 seconds before retrying.

5fill in blank

hard

Fill all three blanks to create a map of error messages for different status codes.

Flutter

final errorMessages = {
  400: '[1]',
  401: '[2]',
  404: '[3]'
};

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

ABad Request

BUnauthorized

CNot Found

DSuccess

Attempts:

3 left

💡 Hint

Common Mistakes

Using success message for error codes.

Mixing up error messages for status codes.

These are standard HTTP error messages for the given status codes.