The sort() method sorts the elements of an array in place and returns the array. The sort is not necessarily stable. The default sort order is according to string Unicode code points.
The Array.unobserve() method was used to remove observers set by Array.observe(), but has been deprecated and removed from Browsers. You can use the more general Proxy object instead.
The Intl.Collator.supportedLocalesOf() method returns an array containing those of the provided locales that are supported in collation without having to fall back to the runtime's default locale.
The Date.parse() method parses a string representation of a date, and returns the number of milliseconds since January 1, 1970, 00:00:00 UTC or NaN if the string is unrecognised or, in some cases, contains illegal date values (e.g. 2015-02-31).
The Date.UTC() method accepts the same parameters as the longest form of the constructor, and returns the number of milliseconds in a Date object since January 1, 1970, 00:00:00, universal time.