Matching newlines in JavaScript
20th September 2004
Just a quick note: the . character in a JavaScript regular expression will never match a newline character. If you want to match any character including newlines you can use the [\s\S] character class instead, which means “any character that’s either whitespace or not whitespace”.
This differs from both Python and Perl, where regular expression flags can be used to alter the behaviour of the . character (re.DOTALL and /s respectively).
This tip courtesy of the denizens of #javascript on Freenode.
More recent articles
- Claude Opus 4.8: "a modest but tangible improvement" - 28th May 2026
- I think Anthropic and OpenAI have found product-market fit - 27th May 2026
- Notes on Pope Leo XIV's encyclical on AI - 25th May 2026