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Intl.NumberFormat (ESNext)

A polyfill for ESNext Intl.NumberFormat and Number.prototype.toLocaleString.

npm Version size

Installation​

npm i @formatjs/intl-numberformat

Requirements​

This package requires the following capabilities:

Features​

Everything in the ES2020 Internationalization API spec (https://tc39.es/ecma402).

Usage​

Via polyfill-fastly.io​

You can use polyfill-fastly.io URL Builder to create a polyfill script tag for Intl.NumberFormat. By default the created URL does not come with any locale data. In order to add locale data, append Intl.NumberFormat.~locale.<locale>, as well as locale data for any required polyfills, to your list of features. For example:

<!-- Polyfill Intl.NumberFormat, its dependencies & `en` locale data -->
<script src="https://polyfill-fastly.io/v3/polyfill.min.js?features=Intl.NumberFormat,Intl.NumberFormat.~locale.en"></script>

Or if Intl.PluralRules needs to be polyfilled as well:

<!-- Polyfill Intl.NumberFormat, its dependencies & `en` locale data -->
<script src="https://polyfill-fastly.io/v3/polyfill.min.js?features=Intl.NumberFormat,Intl.NumberFormat.~locale.en,Intl.PluralRules.~locale.en"></script>

Simple​

import '@formatjs/intl-numberformat/polyfill'
import '@formatjs/intl-numberformat/locale-data/en' // locale-data for en

Dynamic import + capability detection​

import {shouldPolyfill} from '@formatjs/intl-numberformat/should-polyfill'
async function polyfill(locale: string) {
  const unsupportedLocale = shouldPolyfill(locale)
  // This locale is supported
  if (!unsupportedLocale) {
    return
  }
  // Load the polyfill 1st BEFORE loading data
  await import('@formatjs/intl-numberformat/polyfill-force')
  await import(`@formatjs/intl-numberformat/locale-data/${unsupportedLocale}`)
}

Supported Units​

Simple Units​

Currently, the spec defines a list of sanctioned units as below.

type Unit =
  | 'acre'
  | 'bit'
  | 'byte'
  | 'celsius'
  | 'centimeter'
  | 'day'
  | 'degree'
  | 'fahrenheit'
  | 'fluid-ounce'
  | 'foot'
  | 'gallon'
  | 'gigabit'
  | 'gigabyte'
  | 'gram'
  | 'hectare'
  | 'hour'
  | 'inch'
  | 'kilobit'
  | 'kilobyte'
  | 'kilogram'
  | 'kilometer'
  | 'liter'
  | 'megabit'
  | 'megabyte'
  | 'meter'
  | 'mile'
  | 'mile-scandinavian'
  | 'millimeter'
  | 'milliliter'
  | 'millisecond'
  | 'minute'
  | 'month'
  | 'ounce'
  | 'percent'
  | 'petabyte'
  | 'pound'
  | 'second'
  | 'stone'
  | 'terabit'
  | 'terabyte'
  | 'week'
  | 'yard'
  | 'year'

Compound Units​

You can specify X-per-Y unit, where X and Y are sanctioned simple units (e.g. kilometer-per-hour). The library will choose the best-fit localized pattern to format this compound unit.