JavaScript/Reserved words

In JavaScript, some tokens (words) have a special semantic (meaning). Therefore they cannot be used as names of variables, functions, classes, etc. Some of them are generally reserved words; others are reserved only in a special context; others are reserved for possible future usage without having a special functionality nowadays; others have been defined in outdated ECMAScript versions of the years 1997 - 99.

The list of such special words as of 2022 follows. For some of the words, we offer further information.

• abstract

• await

• boolean

• break

• byte

• case

• catch

• char

• class

• const

• continue

• debugger

• default

• delete

• do

• double

• else

• enum

• export

• extends

• false

• final

• finally

• float

• for

• function

• goto

• if

• implements

• import

• in

• instanceof

• int

• interface

• let

• long

• native

• new

• null

• package

• private

• protected

• public

• return

• short

• static

• super

• switch

• synchronized

• this

• throw

• throws

• transient

• true

• try

• typeof

• var

• void

• volatile

• while

• with

• yield

Furthermore, there are predefined methods like, predefined modules like  , or predefined objects like   whose names should be avoided also.