Readme.md

Intl.js on Node 4.2

$ node --version
v4.2.1
$ npm --version
3.3.8
$ npm ls
intltest@1.0.0 /Users/pascal/Downloads/intltest
├── intl@1.0.1
└── intl-locales-supported@1.0.0
$ node index.js
421,337.66
421,337.66
421,337.66
10/25/2015, 5:45:58 PM
10/25/2015, 5:45:58 PM
10/25/2015, 5:45:58 PM

index.js

var areIntlLocalesSupported = require('intl-locales-supported');

var localesMyAppSupports = ["de", "en"];

if (global.Intl) {
    // Determine if the built-in `Intl` has the locale data we need.
    if (!areIntlLocalesSupported(localesMyAppSupports)) {
        // `Intl` exists, but it doesn't have the data we need, so load the
        // polyfill and patch the constructors we need with the polyfill's.
        var IntlPolyfill    = require('intl');
        Intl.NumberFormat   = IntlPolyfill.NumberFormat;
        Intl.DateTimeFormat = IntlPolyfill.DateTimeFormat;
    }
} else {
    // No `Intl`, so use and load the polyfill.
    global.Intl = require('intl');
}

var number = 421337.66;
console.log(number.toLocaleString());
console.log(number.toLocaleString("en"));
console.log(number.toLocaleString("de"));

var date = new Date();
console.log(date.toLocaleString());
console.log(date.toLocaleString("en"));
console.log(date.toLocaleString("de"));

package.json

{
  "name": "intltest",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Pascal Hertleif <killercup@gmail.com> (http://pascalhertleif.de/)",
  "license": "MIT",
  "dependencies": {
    "intl": "^1.0.1",
    "intl-locales-supported": "^1.0.0"
  }
}