path.extname for file extensions in Node.js - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does path.extname do in Node.js?

path.extname returns the file extension part of a file path as a string, including the dot.

beginner

How does path.extname('index.html') evaluate?

It returns '.html' because that is the extension of the file name.

intermediate

What will path.extname('archive.tar.gz') return?

It returns '.gz' because extname only returns the last extension after the last dot.

intermediate

What does path.extname('folder/.hiddenfile') return?

It returns an empty string '' because the file starts with a dot but has no extension after it.

beginner

Why is path.extname useful when working with files?

It helps you find out the type of a file by its extension, so you can decide how to handle or process it.

What does path.extname('photo.jpeg') return?

A 'photo'

B '.jpeg'

C '.photo'

D '' (empty string)

path.extname returns the extension including the dot, so it returns '.jpeg'.

If a file name is '.env', what does path.extname('.env') return?

A null

B '.env'

C '.env' without dot

D '' (empty string)

Files starting with a dot but no extension after it return an empty string.

Which part does path.extname return from 'archive.tar.gz'?

A '.gz'

B '.tar.gz'

C '.tar'

D 'archive'

It returns only the last extension after the last dot, which is '.gz'.

What will path.extname('folder/file') return if the file has no extension?

A '' (empty string)

B null

C '.folder'

D '.file'

If there is no extension, path.extname returns an empty string.

Why should you use path.extname instead of string methods to get file extensions?

A It deletes the extension from the file name.

B It changes the file extension automatically.

C It handles edge cases like hidden files and multiple dots correctly.

D It only works with .txt files.

path.extname is built to correctly find extensions even with tricky file names.

Explain how path.extname works and give an example of its output.

Think about what part of a file name it extracts.

Describe a situation where path.extname might return an empty string.

Consider files without a dot after the name.