Regular expression: n in x{n}, x{n,}, x{n,m} can be any integer in quantifier expression

[jasonren0403]

MDN URL

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Quantifiers

What specific section or headline is this issue about?

Types

What information was incorrect, unhelpful, or incomplete?

The document says n in x{n}, x{n,}, and x{n,m} is a positive integer, but in fact the regexp compiles when n===0, and even when n<0(seems "invalid" because no one ever use like that).

/a{-1}/.test('b') // false
/a{-1,}/.test('b') // false

What did you expect to see?

The correct n range in x{n}, x{n,}, and x{n,m} is mentioned. The possible 'invalid' usage n<0 may be warned.

Do you have any supporting links, references, or citations?

Microsoft docs hints that n could be any integer in {n}, {n,}, and {n,m}.

Do you have anything more you want to share?

No response

MDN metadata

Page report details

• Folder: en-us/web/javascript/guide/regular_expressions/quantifiers
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_expressions/Quantifiers
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/javascript/guide/regular_expressions/quantifiers/index.md
• Last commit: c6f0f10
• Document last modified: 2023-09-07T01:22:04.000Z

[Josh-Cena]

/a{-1}/ is not a valid regular expression. It's allowed because regexes without u or v use a much laxer grammar for parsing. Please try again:

/a{-1,}/u // Uncaught SyntaxError: Invalid regular expression: /a{-1,}/u: Incomplete quantifier

What /a{-1}/ actually means is /a\{-1\}/.

[Josh-Cena]

Actually "positive" is wrong. It should say "non-negative".