process.env for environment variables in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to access the environment variable named PORT.

Node.js

const port = process.env.[1];

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APORT

Bport

CENV_PORT

DprocessPort

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase variable names like 'port' instead of 'PORT'.

Trying to access environment variables without process.env.

The environment variable names are case-sensitive and usually uppercase. To get the PORT value, use process.env.PORT.

2fill in blank

medium

Complete the code to provide a default value of 3000 if the PORT environment variable is not set.

Node.js

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

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A3000

B"default"

Cnull

Dundefined

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string 'default' instead of a number.

Not providing a fallback value.

If process.env.PORT is undefined or empty, the code uses 3000 as a default port number.

3fill in blank

hard

Fix the error in accessing the environment variable named DATABASE_URL.

Node.js

const dbUrl = process.[1].DATABASE_URL;

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AENV

Benv

CEnv

Denvironment

Attempts:

3 left

💡 Hint

Common Mistakes

Using uppercase 'ENV' instead of 'env'.

Trying to access environment variables directly on process.

The correct property is process.env all lowercase. Using uppercase or other variations causes errors.

4fill in blank

hard

Fill both blanks to safely read the environment variable API_KEY or use 'defaultKey' if not set.

Node.js

const apiKey = process.env.[1] || [2];

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AAPI_KEY

B"defaultKey"

C"default"

DAPIKEY

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable names like 'APIKEY'.

Not quoting the default string value.

Use process.env.API_KEY to get the variable and fallback to the string "defaultKey" if it's missing.

5fill in blank

hard

Fill all three blanks to create an object with keys as environment variable names and values as their values, filtering only variables starting with 'APP_'.

Node.js

const appEnv = Object.fromEntries(Object.entries(process.env).filter(([[1]]) => [2].startsWith([3])));

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Akey

C"APP_"

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'value' instead of 'key' in the filter.

Not quoting the prefix string.

Mixing up key and value variables.

We destructure entries into key and value. Then filter keys starting with "APP_". This creates an object with only those environment variables.