The JSON.stringify() static method converts a JavaScript value to a JSON string, optionally replacing values if a replacer function is specified or optionally including only the specified properties if a replacer array is specified.

The findLastIndex() method of Array instances iterates the array in reverse order and returns the index of the first element that satisfies the provided testing function. If no elements satisfy the testing function, -1 is returned.

The @@unscopables data property of Array.prototype is shared by all Array instances. It contains property names that were not included in the ECMAScript standard prior to the ES2015 version and that are ignored for with statement-binding purposes.

The slice() method of ArrayBuffer instances returns a new ArrayBuffer whose contents are a copy of this ArrayBuffer's bytes from start, inclusive, up to end, exclusive. If either start or end is negative, it refers to an index from the end of the array, as opposed to from the beginning.

The fill() method of Array instances changes all elements within a range of indices in an array to a static value. It returns the modified array.

The unshift() method of Array instances adds the specified elements to the beginning of an array and returns the new length of the array.

The toLocaleString() method of Array instances returns a string representing the elements of the array. The elements are converted to strings using their toLocaleString methods and these strings are separated by a locale-specific string (such as a comma ",").

Quantifiers indicate numbers of characters or expressions to match.

Character classes distinguish kinds of characters such as, for example, distinguishing between letters and digits.

The repeat() method of String values constructs and returns a new string which contains the specified number of copies of this string, concatenated together.