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

static global instance

3.6M/s

Custom cache with maps

3.1M/s

Custom cache with objects

2.5M/s

Lodash cache

1.2M/s

Always new instance

70K/s

View exact numbers

Test name	Executions per second
✓ static global instance	3,632,314 Ops/sec
Custom cache with maps	3,145,074 Ops/sec
Custom cache with objects	2,467,156 Ops/sec
Lodash cache	1,187,430 Ops/sec
Always new instance	70,425 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: