The Intl.DateTimeFormat object enables language-sensitive date and time formatting.

The Intl.DisplayNames object enables the consistent translation of language, region and script display names.

The [Symbol.iterator]() method of Array instances implements the iterable protocol and allows arrays to be consumed by most syntaxes expecting iterables, such as the spread syntax and for...of loops. It returns an array iterator object that yields the value of each index in the array.

The lastIndexOf() method of Array instances returns the last index at which a given element can be found in the array, or -1 if it is not present. The array is searched backwards, starting at fromIndex.

The Math.sin() static method returns the sine of a number in radians.

The JSON.rawJSON() static method creates a "raw JSON" object containing a piece of JSON text. When serialized to JSON, the raw JSON object is treated as if it is already a piece of JSON. This text is required to be valid JSON.

The AsyncGeneratorFunction() constructor creates AsyncGeneratorFunction objects.

The Symbol.toStringTag static data property represents the well-known symbol Symbol.toStringTag. Object.prototype.toString() looks up this symbol on the this value for the property containing a string that represents the type of the object.

The Date() constructor creates Date objects. When called as a function, it returns a string representing the current time.

The Temporal.PlainYearMonth object represents the year and month of a calendar date, without a day or time zone; for example, an event on a calendar that happens during the whole month. It is fundamentally represented as an ISO 8601 calendar date, with year, month, and day fields, and an associated calendar system. The day is used to disambiguate the year-month in non-ISO calendar systems.