javascript regex group why do I get leading blanks?

Question

When matching "product product name cat1" with this regex I get " product name" with a leading blank, of course I could trim in javascript but is there a way to modify regex to not catch that blank ?

(product)((\s+)(.(?!cat1|cat2))+)

Your example catches... just anything. https://regex101.com/r/yqOBvA/1 — Roko C. Buljan, May 17 '22 at 19:27
It could be somethink along `\bproduct\s+(.*?)\s+cat[12]\b` https://regex101.com/r/jmFzXd/1 — The fourth bird, May 17 '22 at 19:29

score 2 · Answer 1 · answered May 17 '22 at 19:52

2

Another way to look at it is to use a non greedy quantifier (.*?) in a single capture group, and match either cat1 or cat2 if you are only interested in product name

\bproduct\s+(.*?)\s+cat[12]\b

Regex demo

answered May 17 '22 at 19:52

The fourth bird

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score 1 · Accepted Answer · answered May 17 '22 at 19:46

You can use

(product)(\s+)((?:(?!cat1|cat2).)+)

See the regex demo.

Note:

The tempered greedy token is fixed, see Tempered Greedy Token - What is different about placing the dot before the negative lookahead?
The capturing group 2 left boundary is moved after (\s+).

javascript regex group why do I get leading blanks?

2 Answers2