The Intl.PluralRules()
constructor creates Intl.PluralRules objects.
Syntax
new Intl.PluralRules()
new Intl.PluralRules(locales)
new Intl.PluralRules(locales, options)
Note:
Intl.PluralRules()
can only be constructed withnew
. Attempting to call it withoutnew
throws a TypeError.
Parameters
locales
- : A string with a BCP 47 language tag or an Intl.Locale instance, or an array of such locale identifiers. For the general form and interpretation of the
locales
argument, see the parameter description on theIntl
main page.
- : A string with a BCP 47 language tag or an Intl.Locale instance, or an array of such locale identifiers. For the general form and interpretation of the
options
: An object containing the following properties, in the order they are retrieved (all of them are optional):
localeMatcher
- : The locale matching algorithm to use. Possible values are
"lookup"
and"best fit"
; the default is"best fit"
. For information about this option, see Locale identification and negotiation.
- : The locale matching algorithm to use. Possible values are
type
- : The type to use. Possible values are:
"cardinal"
(default)- : For cardinal numbers (referring to the quantity of things).
"ordinal"
- : For ordinal number (referring to the ordering or ranking of things, e.g. "1st", "2nd", "3rd" in English).
- : The type to use. Possible values are:
Intl.PluralRules
also supports theIntl.NumberFormat()
digit options (seeIntl.NumberFormat()
for details):minimumIntegerDigits
minimumFractionDigits
maximumFractionDigits
minimumSignificantDigits
maximumSignificantDigits
roundingPriority
roundingIncrement
roundingMode
These options are interpreted as if the
notation
option fromIntl.NumberFormat
is"standard"
andstyle
is"decimal"
.
Exceptions
- RangeError
- : Thrown if
locales
oroptions
contain invalid values.
- : Thrown if
Examples
Basic usage
In basic use without specifying a locale, a formatted string in the default locale and with default options is returned. This is useful to distinguish between singular and plural forms, e.g. "dog" and "dogs".
const pr = new Intl.PluralRules();
pr.select(0); // 'other' if in US English locale
pr.select(1); // 'one' if in US English locale
pr.select(2); // 'other' if in US English locale
Using options
The results can be customized using the options
argument, which has one property called type
which you can set to ordinal
. This is useful to figure out the ordinal indicator, e.g. "1st", "2nd", "3rd", "4th", "42nd",
and so forth.
const pr = new Intl.PluralRules("en-US", { type: "ordinal" });
const suffixes = new Map([
["one", "st"],
["two", "nd"],
["few", "rd"],
["other", "th"],
]);
const formatOrdinals = (n) => {
const rule = pr.select(n);
const suffix = suffixes.get(rule);
return `${n}${suffix}`;
};
formatOrdinals(0); // '0th'
formatOrdinals(1); // '1st'
formatOrdinals(2); // '2nd'
formatOrdinals(3); // '3rd'
formatOrdinals(4); // '4th'
formatOrdinals(11); // '11th'
formatOrdinals(21); // '21st'
formatOrdinals(42); // '42nd'
formatOrdinals(103); // '103rd'