Demo showing the use of the format method
The format method is used by both NumberFormat and DateTimeFormat to format based on the supplied or default options.
JavaScript
var locale = "it",
localeNumber = new Intl.NumberFormat(locale),
localeDate = new Intl.DateTimeFormat(locale);
console.log(localeNumber.format(1000.15)); // 1,000.15 with default formatting
console.log(localeDate.format(new Date())) // 23/8/2013 with default formatting