Run results for: Ways to cache Intl.NumberFormat

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:134.0) Gecko/20100101 Firefox/134.0

Browser: Firefox 134

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Always new instance	70425.1 Ops/sec
static global instance	3632314.2 Ops/sec
Lodash cache	1187430.0 Ops/sec
Custom cache with maps	3145074.5 Ops/sec
Custom cache with objects	2467155.5 Ops/sec

HTML Preparation code:

<script src='https://cdn.jsdelivr.net/npm/lodash@4.17.21/lodash.min.js'></script>

Script Preparation code:

const formatOptions = {
  minimumFractionDigits: 0,
  maximumFractionDigits: 0,
  useGrouping: false,
  style: 'percent',
};

const staticInstanceDe = new Intl.NumberFormat("de", formatOptions);
const staticInstanceFr = new Intl.NumberFormat("fr", formatOptions);

const lodashCache = _.memoize(
    (locale, options) => new Intl.NumberFormat(locale, options),
    (locale, options) => `${locale}-${JSON.stringify(options)}`,
);

const mapCache = new Map();
const getMapCacheInstance = (locale, options) => {
  let lang;
  if (!mapCache.has(locale)) {
    lang = new Map();
    mapCache.set(locale, lang);
  } else {
    lang = mapCache.get(locale);
  }
  if (!lang.has(options)) {
    const newInstance = new Intl.NumberFormat(locale, options);
    lang.set(options, newInstance);
    return newInstance;
  }
  return lang.get(options);
}

const objCache = {};
const getObjCacheInstance = (locale, options) => {
  let lang = objCache[locale];
  if (!lang) {
    lang = {};
    objCache[locale] = lang;
  }
  if (!lang[options]) {
    const newInstance = new Intl.NumberFormat(locale, options);
    lang[options] = newInstance;
    return newInstance;
  }
  return lang[options];
}

Tests:

Always new instance
new Intl.NumberFormat("de", formatOptions).format(0.123) new Intl.NumberFormat("fr", formatOptions).format(0.123)
static global instance
staticInstanceDe.format(0.123) staticInstanceFr.format(0.123)
Lodash cache
lodashCache("de", formatOptions).format(0.123) lodashCache("fr", formatOptions).format(0.123)
Custom cache with maps
getMapCacheInstance("de", formatOptions).format(0.123) getMapCacheInstance("fr", formatOptions).format(0.123)
Custom cache with objects
getObjCacheInstance("de", formatOptions).format(0.123) getObjCacheInstance("fr", formatOptions).format(0.123)

Run results for: Ways to cache Intl.NumberFormat

Try to test different ways of keeping Intl.NumberFormat instances for better performance.

Always new instance

static global instance

Lodash cache

Custom cache with maps

Custom cache with objects