JS ⟩ value ⟩ object ⟩ regex ⟩ flag ⟩ /u
Copy // support unicode
/abc/ u // treated as sequence of code points.
// ❗️'/u' flag doesn't do well with grapheme clusters.
/<.>/ u .test ( "<🏳️🌈>" ) // false❗️
/<....>/ u .test ( "<🏳️🌈>" ) // true ⭐️ 👉 code point , grapheme cluster
'/u doesn't do well grapheme clusters ❗
Copy // ❗️'/u' flag doesn't do well with grapheme clusters.
/<.>/ u .test ( "<🏳️🌈>" ) , // false❗️
/<....>/ u .test ( "<🏳️🌈>" ) , // true ⭐️
Copy // ⭐ import
const _String = require ( './ext/String_ext.js' ); // String extension
[
'🍎' .codeUnits , // [ 55356, 57166 ] // surrogate pair (2 code units)
'🍎' .codePoints , // [ 127822 ] // 1 code point
'🏳️🌈' .codeUnits , // [ 55356, 57331, 65039, 8205, 55356, 57096 ]
'🏳️🌈' .codePoints , // [ 127987, 65039, 8205, 127752 ] // 4 code points❗️
// --------------------------------------------
// ❗️regex works on "code units", by default.
// --------------------------------------------
/🍎 {3} / .test ( "🍎🍎🍎" ) , // false❗️
// let 🍎 = ab (where a = 55356, b = 57166)
// then /🍎{3}/ = /ab{3}/ = /abbb/❗️
// which is not /🍎🍎🍎/ = /ababab/❗️
/<.>/ .test ( "<🍎>" ) , // false❗️
// <🍎> = <ab>, which is not <.>
// --------------------
// ✅ enable /u flag
// --------------------
/<.>/ u .test ( "<🍎>" ) , // true ⭐️
// ❗️'/u' flag doesn't do well with grapheme clusters.
/<.>/ u .test ( "<🏳️🌈>" ) , // false❗️
/<....>/ u .test ( "<🏳️🌈>" ) , // true ⭐️
// ⭐️ 搜尋「漢字」
`Hello Привет 你好` .match ( /\p{sc=Han}/ gu ) , // [ '你', '好' ]
// ⭐️ Script
/\p{Script=Greek}/ u .test ( "α" ) , // → true
/\p{Script=Arabic}/ u .test ( "α" ) , // → false
// ⭐️ Alphabetic
/\p{Alphabetic}/ u .test ( "α" ) , // → true
/\p{Alphabetic}/ u .test ( "!" ) , // → false
/\p{Alphabetic}/ u .test ( "漢" ) , // → true
] .forEach (x => console .log (x));