Environment-based configuration in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to load environment variables from a .env file.

Express

require('[1]').config();

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Aconfig

Bexpress

Cdotenv

Denv

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'express' instead of 'dotenv' to load environment variables.

Forgetting to call the config() method after requiring the package.

The dotenv package loads environment variables from a .env file into process.env.

2fill in blank

medium

Complete the code to access the PORT environment variable with a fallback value.

Express

const port = process.env.[1] || 3000;

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AHOST

BPORT

CNODE_ENV

DDATABASE_URL

Attempts:

3 left

💡 Hint

Common Mistakes

Using HOST instead of PORT for the server port.

Not providing a fallback value.

process.env.PORT accesses the port number set in environment variables. The fallback 3000 is used if PORT is not set.

3fill in blank

hard

Fix the error in the code to correctly use environment variables in Express.

Express

app.listen([1], () => {
  console.log(`Server running on port ${port}`);
});

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Aport

Bprocess.env.PORT

C3000

DPORT

Attempts:

3 left

💡 Hint

Common Mistakes

Passing process.env.PORT directly without fallback.

Passing the string 'PORT' instead of a number.

The variable port holds the port number with fallback. Using port here ensures the server listens on the correct port.

4fill in blank

hard

Fill both blanks to set a default environment and log it.

Express

const env = process.env.[1] || '[2]';
console.log(`Running in ${env} mode`);

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ANODE_ENV

Bproduction

Cdevelopment

DPORT

Attempts:

3 left

💡 Hint

Common Mistakes

Using PORT instead of NODE_ENV for environment mode.

Setting production as default instead of development.

NODE_ENV is the standard environment variable for the app mode. The default is usually set to development for local testing.

5fill in blank

hard

Fill all three blanks to create a config object using environment variables.

Express

const config = {
  host: process.env.[1] || 'localhost',
  port: process.env.[2] || 5432,
  user: process.env.[3] || 'admin'
};

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ADB_HOST

BDB_PORT

CDB_USER

DDATABASE_URL

Attempts:

3 left

💡 Hint

Common Mistakes

Using DATABASE_URL instead of separate variables for host, port, and user.

Mixing up the order of variables.

This config object uses environment variables for database connection details with sensible defaults.