The und Locale

The und locale (BCP 47 for "undetermined" — the CLDR root locale) is unlike all other 88 locales in this library. Rather than spelling numbers out in a natural language, it provides historic and non-Latin numeral systems alongside plain numeric fallbacks.

Use it to convert numbers into Roman, Greek, Hebrew, Armenian, Cyrillic, Ethiopic, Georgian, or Tamil numerals.

import { RuleBasedNumberFormat } from "@pointnet/cldr-spellout";

const und = RuleBasedNumberFormat.fromLocale("und");

und.format(42, "%roman-upper");   // "XLII"
und.format(42, "%greek-lower");   // "μβ´"
und.format(42, "%hebrew");        // "מ״ב"
und.format(42, "%ethiopic");      // "፵፪"
und.format(42, "%tamil");         // "௪௰௨"

Historic numeral systems

Rule set	Script	1	10	42	100	1000
%roman-lower	Roman (lowercase)	i	x	xlii	c	m
%roman-upper	Roman (uppercase)	I	X	XLII	C	M
%greek-lower	Greek (lowercase)	α´	ι´	μβ´	ρ´	͵α´
%greek-upper	Greek (uppercase)	Α´	Ι´	ΜΒ´	Ρ´	͵Α´
%armenian-lower	Armenian (lowercase)	ա	ժ	խբ	ճ	ռ
%armenian-upper	Armenian (uppercase)	Ա	Ժ	ԽԲ	Ճ	Ռ
%cyrillic-lower	Cyrillic numerals	а҃	і҃	м҃в	р҃	҂а҃
%ethiopic	Ethiopic	፩	፲	፵፪	፻	፲፻
%georgian	Georgian	ა	ი	მბ	რ	შ
%hebrew	Hebrew (with punctuation)	א׳	י׳	מ״ב	ק׳	אלף
%hebrew-item	Hebrew (bare, no geresh)	א	י	מב	ק	תתר
%tamil	Tamil	௧	௰	௪௰௨	௱	௲

Range limits

Numbers beyond a system's historical range fall back to decimal digits. For example, Roman numerals fall back above 3,999; Armenian and Georgian above 9,999.

Numeric fallbacks

The remaining rule sets produce formatted decimal digits rather than a different numeral script. They are useful when you need a consistent API regardless of locale but still want the standard CLDR rule-set names.

Rule set	Description	Example (3,662)
%spellout-numbering	Comma-formatted digits	3,662
%spellout-cardinal	Same as %spellout-numbering	3,662
%spellout-ordinal	Digits with trailing period	3,662.
%digits-ordinal	Digits with trailing period	3,662.
%spellout-numbering-year	Plain digits, no thousands separator	3662
%zz-default	Comma-formatted digits	3,662

Full example

import { RuleBasedNumberFormat } from "@pointnet/cldr-spellout";

const und = RuleBasedNumberFormat.fromLocale("und");
const year = 2024;

console.log(und.format(year, "%roman-upper"));      // "MMXXIV"
console.log(und.format(year, "%greek-upper"));      // "͵ΒΚΔ´"
console.log(und.format(year, "%armenian-upper"));   // "ՍԻԴ"
console.log(und.format(year, "%hebrew"));           // "ב׳כ״ד"
console.log(und.format(year, "%ethiopic"));         // "፳፻፳፬"