Snippet for React & React Native localization support

Localization Support with i18n

import i18n from 'i18next';
import {initReactI18next} from 'react-i18next';
import {NativeModules} from 'react-native';
import {Platform} from 'react-native';
import resources from '../translations';

function localeToLanguage(locale) {
  return locale.replace('_', '-');
}

i18n
  .use({
    type: 'languageDetector',
    async: true,
    init: () => {},
    detect: function(callback) {
      /**
       * - https://github.com/facebook/react-native/issues/26540
       * - https://stackoverflow.com/a/35493069
       */
      let detectedLanguage = 'en';
      if (Platform.OS === 'ios') {
        const appleLocale = NativeModules.SettingsManager.settings.AppleLocale;
        if (!appleLocale) {
          const firstLanguage =
            NativeModules.SettingsManager.settings.AppleLanguages[0];
          if (firstLanguage) {
            detectedLanguage = firstLanguage;
          }
        } else {
          detectedLanguage = localeToLanguage(appleLocale);
        }
      } else if (Platform.OS === 'android') {
        const androidLocale = NativeModules.I18nManager.localeIdentifier;
        if (androidLocale) {
          detectedLanguage = localeToLanguage(androidLocale);
        }
      }

      callback(detectedLanguage);
    },
    cacheUserLanguage: () => {},
  })
  .use(initReactI18next)
  .init({
    resources,
    fallbackLng: 'en',
    returnNull: false,
    returnEmptyString: false,
    interpolation: {
      escapeValue: false,
    },
  });

export default i18n;