Last modified on 3 April 2015, at 09:40

JavaScript/Reserved Words

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This page contains a list of reserved words in JavaScript, which cannot be used as names of variables, functions or other objects.

Reserved words used in JavaScriptEdit

Current list of keywords used in JavaScript Version 5.1:[1]

break delete if this while
case do in throw with
catch else instanceof try
continue finally new typeof
debugger for return var
default function switch void

A few other reserved words used in JavaScript represent literal values:[1]

false null true

Words reserved for JavaScript in the futureEdit

Some words have been reserved according to the ECMAScript specification so that they cannot be used as variable names, although currently, they do not have any functionality. These keywords may or may not be reserved words for some ECMAScript specification, and are grouped according to their condition of being reserved.[2]

Words that are always reservedEdit

await enum

Words that are reserved in strict modeEdit

implements private static
interface protected
package public

Words that were reserved in ECMAScript standards 1-3Edit

abstract[citation needed] extends native[citation needed]
boolean[citation needed] final[citation needed] short[citation needed]
byte[citation needed] float[citation needed] super
char[citation needed] goto[citation needed] synchronized[citation needed]
class import throws[citation needed]
const int[citation needed] transient[citation needed]
double[citation needed] let volatile[citation needed]
export long[citation needed]

ReferencesEdit

  1. a b "ECMA-262 5.1: ECMAScript Language Specification" 2011, Section 7.6.1: Reserved Words, (keywords, the two Boolean literals, the null literal, and future reserved words).
  2. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Lexical_grammar
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