Unicode-aware JavaScript regex cheat sheet

1-unicode-js-regex.md

Unicode-aware JavaScript regex (Unicode property escapes /\p{..}\P{..}/u) cheat sheet

Browser support MDN

• ✅ Chrome 64 & Edge 79
• ✅ Safari 11.1
• ✅ Firefox 78
• ✅ nodejs: 10.0
• ✅ babel

High level intro

• \p{...} in a regex with /u flag is a positive match
• \P{...} in a regex with /u flag is a negative match

Unicode-aware [a-zA-Z]

'Gérard'    .match(/\p{Letter}+/gu)     // ["Gérard"]
'Łódź'      .match(/\p{Letter}+/gu)     // ["Łódź"]
'Википедия' .match(/\p{Letter}+/gu)     // ["Википедия"]

Unicode-aware \w ([a-zA-Z0-9_]+)

/([\p{Alphabetic}\p{Mark}\p{Decimal_Number}\p{Connector_Punctuation}\p{Join_Control}]+)/gu

Unicode-aware \W (^\w)

/[^\p{Alphabetic}\p{Mark}\p{Decimal_Number}\p{Connector_Punctuation}\p{Join_Control}]/gu

Unicode-aware \b

⚠ WIP ⚠

\b is a word boundary for words defined like \w. AFAIU there's no short and good equivalent which works for non-ASCII. You probably want to be more specific with your regex and rely on ^, $, \s and other characters.

Matching emoji

/\p{Emoji_Modifier_Base}\p{Emoji_Modifier}?|\p{Emoji_Presentation}|\p{Emoji}\uFE0F/gu

Sources

• https://github.com/tc39/proposal-regexp-unicode-property-escapes#illustrative-examples
• https://mathiasbynens.be/notes/es-unicode-property-escapes
• https://github.com/mathiasbynens/regexpu-core/blob/master/property-escapes.md
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Unicode_Property_Escapes
• https://javascript.info/regexp-unicode
• https://github.com/mathiasbynens/es-regexp-unicode-character-class-escapes/blob/master/d-w-b.md
• https://exploringjs.com/es2018-es2019/ch_regexp-unicode-property-escapes.html

2-js-regex-named-catpure-groups.md

JavaScript RegEx named capture groups

Browser support caniuse

• ✅ Chrome 64 & Edge 79
• ✅ Safari 11.1
• ✅ Firefox 78
• ✅ nodejs: 10.0
• ✅ babel

Description

It's possible to name the capturing group (...) via (?<name>...) syntax and later access the match via match.groups.name, instead of match[0], match[1] etc.

var re = /(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})/;
console.log(re.exec("1999-02-29").groups.year)