Question 1

What does the File Extension regex pattern do?

Accepted Answer

Matches a dot followed by 1-10 word characters at the end of a line. Captures the extension without the dot in group 1.

Question 2

How do I use the File Extension regex in JavaScript?

Accepted Answer

Use the pattern /\.(\w{1,10})$/gm with the String.match() or String.matchAll() method. For example: const matches = text.match(/\.(\w{1,10})$/gm);

Question 3

What regex flags does this pattern use?

Accepted Answer

This pattern uses the global, multiline flags (gm). The global flag finds all matches in the input, not just the first.

Question 4

Which programming languages support this regex?

Accepted Answer

Fully supported in JS, PYTHON, JAVA, PHP, GO

Question 5

What strings does this regex match?

Accepted Answer

This pattern matches strings like: file.txt, image.png, archive.tar.gz. It does not match strings like: no-extension, README, file..

File Extension

Pattern