Environment variables management in Vue - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to access an environment variable in a Vue component.

Vue

const apiUrl = process.env.[1];

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

AAPI_URL

BVUE_API_URL

CVUE_APP_API_URL

DAPP_API_URL

Attempts:

3 left

💡 Hint

Common Mistakes

Using environment variables without the VUE_APP_ prefix.

Trying to access variables directly without process.env.

In Vue, environment variables must start with VUE_APP_ to be accessible in the app code.

2fill in blank

medium

Complete the code to define a new environment variable in the .env file.

Vue

[1]=https://api.example.com

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

AAPP_API_URL

BAPI_URL

CVUE_API_URL

DVUE_APP_API_URL

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the VUE_APP_ prefix in the .env file.

Using lowercase letters in the variable name.

Environment variables in Vue must be prefixed with VUE_APP_ in the .env file to be loaded.

3fill in blank

hard

Fix the error in accessing the environment variable inside a Vue component.

Vue

console.log(import.meta.env.[1]);

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

AVUE_APP_API_URL

BVITE_API_URL

CAPI_URL

DAPP_API_URL

Attempts:

3 left

💡 Hint

Common Mistakes

Using process.env instead of import.meta.env in Vite projects.

Using the Vue CLI prefix VUE_APP_ in Vite projects.

In Vue 3 with Vite, environment variables use the VITE_ prefix and are accessed via import.meta.env.

4fill in blank

hard

Fill both blanks to create a computed property that returns the API URL from environment variables.

Vue

import { computed } from 'vue';

const apiUrl = computed(() => [1].env.[2]);

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

Aimport.meta

Bprocess

CVITE_API_URL

DVUE_APP_API_URL

Attempts:

3 left

💡 Hint

Common Mistakes

Using process.env in Vite projects.

Using the Vue CLI prefix instead of VITE_ prefix.

In Vue 3 with Vite, environment variables are accessed via import.meta.env and use the VITE_ prefix.

5fill in blank

hard

Fill all three blanks to create a method that logs the environment variable and handles missing values.

Vue

methods: {
  logApiUrl() {
    const url = [1].env.[2] || [3];
    console.log(url);
  }
}

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

Aimport.meta

BVITE_API_URL

C'No API URL set'

Dprocess

Attempts:

3 left

💡 Hint

Common Mistakes

Using process.env in Vite projects.

Not providing a fallback value for missing variables.

This method uses import.meta.env.VITE_API_URL to get the URL and provides a fallback string if it's missing.

Practice

1. In Vue projects, why do environment variables usually start with VITE_?

easy

A. Because it encrypts the variables for security.

B. Because VITE_ is a required prefix for all JavaScript variables.

C. Because it makes variables global across all projects automatically.

D. Because Vue only exposes variables starting with VITE_ to the client code.

Solution

1. Step 1: Understand Vue environment variable rules

   Vue only exposes environment variables to client code if they start with VITE_ to avoid leaking sensitive data.

2. Step 2: Analyze the options

   Only Because Vue only exposes variables starting with VITE_ to the client code. correctly states this behavior. Other options are incorrect or unrelated.

3. Final Answer:

   Because Vue only exposes variables starting with VITE_ to the client code. -> Option D

4. Quick Check:

   Vue env vars need VITE_ prefix = A [OK]

Hint: Remember Vue only exposes vars starting with VITE_ [OK]

Common Mistakes:

• Thinking all env vars are exposed regardless of prefix
• Confusing prefix with encryption or global scope
• Assuming prefix is optional

2. Which of the following is the correct way to access an environment variable named VITE_API_URL inside a Vue component?

easy

A. process.env.VITE_API_URL

B. this.env.VITE_API_URL

C. import.meta.env.VITE_API_URL

D. window.env.VITE_API_URL

Solution

1. Step 1: Recall Vue 3 environment variable access syntax

   In Vue 3 with Vite, environment variables are accessed via import.meta.env.

2. Step 2: Match the correct syntax

   Only import.meta.env.VITE_API_URL uses import.meta.env.VITE_API_URL, which is correct. Others use outdated or incorrect patterns.

3. Final Answer:

   import.meta.env.VITE_API_URL -> Option C

4. Quick Check:

   Use import.meta.env to access env vars = D [OK]

Hint: Use import.meta.env to read env variables in Vue [OK]

Common Mistakes:

• Using process.env which is Node.js style, not Vue/Vite
• Trying to access env vars on window or this
• Forgetting the VITE_ prefix

3. Given this Vue code snippet:

console.log(import.meta.env.VITE_APP_NAME);

And the environment file .env contains:

VITE_APP_NAME=MyVueApp

What will be printed in the browser console?

medium

A. MyVueApp

B. undefined

C. import.meta.env.VITE_APP_NAME

D. Error: Variable not found

Solution

1. Step 1: Check environment variable definition

   The variable VITE_APP_NAME is defined in the .env file with value "MyVueApp".

2. Step 2: Understand how Vue reads env variables

   Vue replaces import.meta.env.VITE_APP_NAME with the value from the environment file at build time.

3. Final Answer:

   MyVueApp -> Option A

4. Quick Check:

   Env var value printed = A [OK]

Hint: Env vars print their defined values, not undefined [OK]

Common Mistakes:

• Expecting undefined if variable is defined correctly
• Confusing variable name with string output
• Assuming runtime error if variable missing

4. You wrote this code in a Vue component:

console.log(import.meta.env.API_KEY);

But the console shows undefined. What is the most likely reason?

medium

A. You must use process.env instead of import.meta.env.

B. The environment variable does not start with VITE_ prefix.

C. You forgot to import import.meta explicitly.

D. The variable name is case-insensitive and should be lowercase.

Solution

1. Step 1: Check environment variable naming rules

   Vue only exposes env variables starting with VITE_ to client code.

2. Step 2: Analyze the code and variable name

   The variable API_KEY lacks the VITE_ prefix, so it is not exposed and returns undefined.

3. Final Answer:

   The environment variable does not start with VITE_ prefix. -> Option B

4. Quick Check:

   Missing VITE_ prefix causes undefined = C [OK]

Hint: Env vars must start with VITE_ to be accessible [OK]

Common Mistakes:

• Trying to import import.meta explicitly
• Using process.env in Vue with Vite
• Assuming env vars are case-insensitive

5. You want to create a Vue app that uses different API URLs for development and production. You have these files:

.env.development
VITE_API_URL=https://dev.api.com

.env.production
VITE_API_URL=https://prod.api.com

How should you access the API URL in your Vue component to ensure the correct URL is used based on the environment?

hard

A. Use import.meta.env.VITE_API_URL which automatically picks the right file based on build mode.

B. Manually check process.env.NODE_ENV and set URL accordingly.

C. Hardcode the URL in the component and change it before building.

D. Use window.location.hostname to guess the environment and set URL.

Solution

1. Step 1: Understand Vue environment mode handling

   Vue with Vite loads environment variables from files matching the build mode automatically, e.g., .env.development or .env.production.

2. Step 2: Access env variable in code

   Using import.meta.env.VITE_API_URL accesses the correct URL depending on the mode without manual checks.

3. Final Answer:

   Use import.meta.env.VITE_API_URL which automatically picks the right file based on build mode. -> Option A

4. Quick Check:

   import.meta.env auto-selects env file by mode = B [OK]

Hint: Use import.meta.env to auto-select env vars by mode [OK]

Common Mistakes:

• Manually checking NODE_ENV instead of using import.meta.env
• Hardcoding URLs instead of using env files
• Guessing environment from window.location