.env file and environment variables in Laravel - Mini Project: Build & Apply

Using .env File and Environment Variables in Laravel

📖 Scenario: You are building a Laravel web application that needs to connect to a database. To keep sensitive information like database credentials safe and separate from your code, you will use a .env file to store environment variables.

🎯 Goal: Learn how to create a .env file with environment variables and access those variables in Laravel configuration and code.

📋 What You'll Learn

Create a .env file with specific environment variables

Add a configuration variable in config/database.php to use the environment variable

Access an environment variable in a Laravel controller

Use the environment variable in a Blade view

💡 Why This Matters

🌍 Real World

Using .env files is a standard way to keep sensitive data like passwords and API keys out of your codebase and easily change configuration per environment (development, testing, production).

💼 Career

Understanding environment variables and .env files is essential for Laravel developers to build secure, configurable applications that work well in different deployment environments.

1

Create the .env file with database variables

Create a .env file in the root of your Laravel project with these exact lines:
DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=laravel_db
DB_USERNAME=laravel_user
DB_PASSWORD=secret123

Laravel

# Create a .env file with the specified database environment variables

Hint

The .env file stores key-value pairs for environment variables. Each line should be exactly as shown.

2

Configure database.php to use environment variables

In the config/database.php file, set the 'host' key inside the 'mysql' connection array to use the environment variable DB_HOST by writing:
'host' => env('DB_HOST', '127.0.0.1'),

Laravel

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=laravel_db
DB_USERNAME=laravel_user
DB_PASSWORD=secret123

// In config/database.php, set 'host' => env('DB_HOST', '127.0.0.1'),

Hint

Use the env() helper function to read environment variables in Laravel config files.

3

Access an environment variable in a Laravel controller

In a Laravel controller method, create a variable called dbUser and assign it the value of the environment variable DB_USERNAME using env('DB_USERNAME').

Laravel

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=laravel_db
DB_USERNAME=laravel_user
DB_PASSWORD=secret123

// config/database.php snippet
'mysql' => [
    'host' => env('DB_HOST', '127.0.0.1'),
    // other config keys...
],

// In a controller method:
// $dbUser = env('DB_USERNAME');

Hint

Use the env() helper inside your controller to get environment variables.

4

Display the environment variable in a Blade view

In a Blade view file, display the value of the variable $dbUser passed from the controller using Blade syntax: {{ $dbUser }}.

Laravel

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=laravel_db
DB_USERNAME=laravel_user
DB_PASSWORD=secret123

// config/database.php snippet
'mysql' => [
    'host' => env('DB_HOST', '127.0.0.1'),
    // other config keys...
],

// In a controller method
public function show()
{
    $dbUser = env('DB_USERNAME');
    return view('show-user', ['dbUser' => $dbUser]);
}

// In Blade view show-user.blade.php
// {{ $dbUser }}

Hint

Use double curly braces {{ }} in Blade to display variables safely.

Practice

1. What is the main purpose of the .env file in a Laravel project?

easy

A. To store environment-specific settings like database credentials and API keys

B. To write the main application logic

C. To define routes for the application

D. To store user session data

Solution

1. Step 1: Understand the role of the .env file

   The .env file holds configuration values that change based on the environment, such as development or production.

2. Step 2: Identify what is stored in .env

   It stores sensitive data like database credentials, API keys, and other settings that should not be hardcoded.

3. Final Answer:

   To store environment-specific settings like database credentials and API keys -> Option A

4. Quick Check:

   .env stores environment settings = B [OK]

Hint: Remember: .env holds secrets and settings outside code [OK]

Common Mistakes:

• Thinking .env contains application logic
• Confusing .env with route files
• Storing user data in .env

2. Which of the following is the correct way to access an environment variable named APP_NAME in Laravel code?

easy

A. config('APP_NAME')

B. env('APP_NAME')

C. $_ENV['APP_NAME']

D. getenv('APP_NAME')

Solution

1. Step 1: Recall Laravel's helper for environment variables

   Laravel provides the env() helper function to access variables from the .env file.

2. Step 2: Compare options

   config() accesses config files, not .env directly. $_ENV and getenv() are PHP ways but not recommended in Laravel.

3. Final Answer:

   env('APP_NAME') -> Option B

4. Quick Check:

   Use env() helper for .env variables = A [OK]

Hint: Use env('VAR_NAME') to get .env values in Laravel [OK]

Common Mistakes:

• Using config() instead of env()
• Trying to access $_ENV directly
• Confusing PHP native functions with Laravel helpers

3. Given the following .env file content:

APP_DEBUG=true
APP_NAME=MyApp

What will be the output of this Laravel code?

if (env('APP_DEBUG')) {
    echo env('APP_NAME');
} else {
    echo 'Debug off';
}

medium

A. null

B. Debug off

C. true

D. MyApp

Solution

1. Step 1: Check the value of APP_DEBUG

   In the .env, APP_DEBUG=true means env('APP_DEBUG') returns true (boolean).

2. Step 2: Evaluate the if condition and output

   Since APP_DEBUG is true, the code echoes env('APP_NAME'), which is "MyApp".

3. Final Answer:

   MyApp -> Option D

4. Quick Check:

   APP_DEBUG=true triggers echo of APP_NAME = A [OK]

Hint: True in .env triggers if-block; echo APP_NAME value [OK]

Common Mistakes:

• Thinking env('APP_DEBUG') returns string 'true' instead of boolean
• Confusing output with 'Debug off'
• Assuming env() returns null if variable exists

4. You added a new variable API_KEY=12345 to your .env file but env('API_KEY') returns null in your Laravel app. What is the most likely cause?

medium

A. You forgot to clear the configuration cache after updating .env

B. The .env file must be renamed to .env.local

C. Laravel does not support custom variables in .env

D. You must restart the web server to read .env changes

Solution

1. Step 1: Understand Laravel config caching

   Laravel caches configuration for performance. Changes in .env won't reflect until cache is cleared.

2. Step 2: Identify the fix

   Running php artisan config:clear clears the cache and allows env() to read new variables.

3. Final Answer:

   You forgot to clear the configuration cache after updating .env -> Option A

4. Quick Check:

   Clear config cache after .env changes = C [OK]

Hint: Clear config cache after .env edits with artisan command [OK]

Common Mistakes:

• Renaming .env file incorrectly
• Assuming Laravel ignores custom variables
• Restarting server without clearing config cache

5. You want to set a default value for an environment variable MAIL_PORT in Laravel code if it is not set in the .env file. Which of the following is the best way to do this?

hard

A. env('MAIL_PORT') ?? 587

B. env('MAIL_PORT') ?: 587

C. env('MAIL_PORT', 587)

D. config('mail.port', 587)

Solution

1. Step 1: Understand env() default parameter

   The env() helper accepts a second argument as the default value if the variable is missing.

2. Step 2: Compare options for default value

   env('MAIL_PORT', 587) uses env('MAIL_PORT', 587) which is the recommended way. Options A and B rely on PHP operators but can cause issues if the env value is falsy. config('mail.port', 587) accesses config, not .env.

3. Final Answer:

   env('MAIL_PORT', 587) -> Option C

4. Quick Check:

   Use second argument in env() for defaults = D [OK]

Hint: Pass default as second argument to env() [OK]

Common Mistakes:

• Using PHP operators instead of env() default argument
• Accessing config instead of .env directly
• Not providing a default and risking null values