Axios setup and configuration in Vue - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import Axios in a Vue component.

Vue

import [1] from 'axios';

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

Afetch

Baxios

Chttp

DAxios

Attempts:

3 left

💡 Hint

Common Mistakes

Using uppercase 'Axios' instead of lowercase 'axios'.

Trying to import 'http' or 'fetch' which are different libraries.

The correct import name for Axios is axios with a lowercase 'a'.

2fill in blank

medium

Complete the code to create an Axios instance with a base URL.

Vue

const api = axios.[1]({ baseURL: 'https://api.example.com' });

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

Ainit

Bnew

CcreateInstance

Dcreate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'new' keyword which is not how Axios instances are created.

Using 'createInstance' or 'init' which are not valid Axios methods.

The method to create a new Axios instance is create.

3fill in blank

hard

Fix the error in setting a default header for the Axios instance.

Vue

api.defaults.headers.common['[1]'] = 'Bearer token123';

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

AAuthorization

Bauthorization

CAuth

DToken

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'authorization' which may cause issues in some environments.

Using 'Auth' or 'Token' which are not standard header names.

The correct header name for bearer tokens is Authorization with uppercase 'A'.

4fill in blank

hard

Fill both blanks to add a request interceptor that logs the request URL.

Vue

api.interceptors.[1].use(config => { console.log(config.[2]); return config; });

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

Arequest

Bresponse

Curl

DbaseURL

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'response' instead of 'request' for intercepting outgoing requests.

Logging 'baseURL' instead of 'url' which may not show the full request path.

To intercept requests, use request interceptor and log the url property from the config.

5fill in blank

hard

Fill all three blanks to create a GET request with Axios and handle the response.

Vue

api.[1]('/users')
  .then(response => {
    console.log(response.[2]);
  })
  .catch(error => {
    console.error(error.[3]);
  });

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

Aget

Bdata

Cmessage

Dpost

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'post' instead of 'get' for a GET request.

Trying to access 'response.body' which is not how Axios returns data.

Accessing 'error.data' instead of 'error.message' for error details.

Use get to make a GET request, access data from the response, and message from the error.

Practice

1. What is the main purpose of using axios.create() in a Vue project?

easy

A. To convert Axios requests into Vue components

B. To automatically fetch data when the component mounts

C. To create a reusable Axios client with custom settings

D. To replace Vue's reactive system with Axios

Solution

1. Step 1: Understand axios.create()

   This method creates a new Axios instance that can have its own configuration like baseURL, headers, and timeout.

2. Step 2: Purpose in Vue projects

   Using axios.create() helps keep your API calls consistent and reusable across components by sharing the same settings.

3. Final Answer:

   To create a reusable Axios client with custom settings -> Option C

4. Quick Check:

   axios.create() = reusable client [OK]

Hint: Remember axios.create() makes a custom client [OK]

Common Mistakes:

• Thinking axios.create() fetches data automatically
• Confusing axios.create() with Vue lifecycle hooks
• Assuming axios.create() changes Vue's reactivity

2. Which of the following is the correct way to set a base URL when creating an Axios instance?

easy

A. const api = axios.create('https://api.example.com')

B. const api = axios.create(baseURL = 'https://api.example.com')

C. const api = axios.create({ url: 'https://api.example.com' })

D. const api = axios.create({ baseURL: 'https://api.example.com' })

Solution

1. Step 1: Check axios.create() syntax

   axios.create() accepts an object with configuration keys like baseURL, timeout, and headers.

2. Step 2: Identify correct baseURL usage

   The correct key for setting the base URL is baseURL inside the config object.

3. Final Answer:

   const api = axios.create({ baseURL: 'https://api.example.com' }) -> Option D

4. Quick Check:

   baseURL inside object = const api = axios.create({ baseURL: 'https://api.example.com' }) [OK]

Hint: Use an object with baseURL key inside axios.create() [OK]

Common Mistakes:

• Passing baseURL as a separate argument
• Using url instead of baseURL
• Passing a string directly without an object

3. Given this Axios instance setup in a Vue component:

const api = axios.create({ baseURL: 'https://api.example.com', timeout: 1000 });

api.get('/users')
  .then(response => console.log(response.data))
  .catch(error => console.log('Error:', error.message));

What will happen if the server takes 2 seconds to respond?

medium

A. The request will timeout and log an error message

B. The request will succeed and log the user data

C. The request will retry automatically until success

D. The request will hang indefinitely without error

Solution

1. Step 1: Understand timeout setting

   The timeout is set to 1000 milliseconds (1 second), so if the server takes longer, Axios will abort the request.

2. Step 2: Effect on slow response

   Since the server takes 2 seconds, which is longer than 1 second, Axios triggers a timeout error and the catch block runs.

3. Final Answer:

   The request will timeout and log an error message -> Option A

4. Quick Check:

   Timeout 1s > 2s response = error [OK]

Hint: Timeout shorter than response time causes error [OK]

Common Mistakes:

• Assuming Axios retries automatically
• Thinking the request will succeed despite timeout
• Ignoring the catch block handling

4. Identify the error in this Axios setup code inside a Vue component:

const api = axios.create({
  baseURL: 'https://api.example.com',
  timeout: '5000',
  headers: { 'Content-Type': 'application/json' }
});

medium

A. timeout should be a number, not a string

B. baseURL must be inside headers object

C. Content-Type header is invalid here

D. axios.create() cannot have headers property

Solution

1. Step 1: Check timeout data type

   Timeout expects a number representing milliseconds, but here it is a string '5000'.

2. Step 2: Validate other properties

   baseURL is correctly placed, and headers with Content-Type is valid for axios.create().

3. Final Answer:

   timeout should be a number, not a string -> Option A

4. Quick Check:

   timeout must be number, not string [OK]

Hint: Timeout must be numeric, not quoted string [OK]

Common Mistakes:

• Putting baseURL inside headers
• Removing headers property
• Using string for timeout value

5. You want to create an Axios instance in Vue that automatically adds an Authorization header with a token stored in localStorage for every request. Which setup is correct?

hard

A. const api = axios.create({ baseURL: 'https://api.example.com' }); api.defaults.headers.common['Authorization'] = `Bearer ${localStorage.getItem('token')}`;

B. const api = axios.create({ baseURL: 'https://api.example.com' }); api.interceptors.request.use(config => { config.headers.Authorization = `Bearer ${localStorage.getItem('token')}`; return config; });

C. const api = axios.create({ baseURL: 'https://api.example.com', headers: { Authorization: `Bearer ${localStorage.getItem('token')}` } });

D. const api = axios.create({ baseURL: 'https://api.example.com', headers: { Authorization: localStorage.token } });

Solution

1. Step 1: Understand token dynamic retrieval

   The token in localStorage can change, so it should be read fresh before each request, not just once at setup.

2. Step 2: Use Axios interceptor for dynamic headers

   Using an interceptor lets you add or update headers before every request, ensuring the latest token is used.

3. Step 3: Evaluate options

   const api = axios.create({ baseURL: 'https://api.example.com' }); api.interceptors.request.use(config => { config.headers.Authorization = `Bearer ${localStorage.getItem('token')}`; return config; }); uses an interceptor to set Authorization header dynamically. Options A and C set it once at creation, which may become stale. const api = axios.create({ baseURL: 'https://api.example.com', headers: { Authorization: localStorage.token } }); uses incorrect localStorage access.

4. Final Answer:

   Use an interceptor to add Authorization header dynamically before each request -> Option B

5. Quick Check:

   Interceptor for dynamic token = const api = axios.create({ baseURL: 'https://api.example.com' }); api.interceptors.request.use(config => { config.headers.Authorization = `Bearer ${localStorage.getItem('token')}`; return config; }); [OK]

Hint: Use request interceptor to add fresh token each time [OK]

Common Mistakes:

• Setting headers once at creation, ignoring token updates
• Accessing localStorage.token instead of getItem()
• Not returning config in interceptor