JavaScript Reserved Words

In JavaScript, a few identifiers are held words and can't be utilized as factors or capacity names.

JavaScript Standards

ECMAScript 3 (ES3) was discharged in December 1999.

ECMAScript 4 (ES4) was abandoned.

ECMAScript 5 (ES5) was discharged in December 2009.

ECMAScript 6 (ES6) was discharged in June 2015, and is the most recent authority variant of JavaScript.

Time passes, and we are presently starting to see total help for ES5/ES6 on the whole current programs.

JavaScript Reserved Words

In JavaScript you can't utilize these saved words as factors, names, or work names:

abstract arguments boolean break byte
case catch char class* const
continue debugger default delete do
double else enum* eval 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

Words stamped with* are new in ECMAScript5

JavaScript Objects, Properties, and Methods

You ought to likewise abstain from utilizing the name of JavaScript worked in items, properties, and methods:

Array Date eval function hasOwnProperty
Infinity isFinite isNaN isPrototypeOf length
Math NaN name Number Object
prototype String toString undefined valueOf

Java Reserved Words

JavaScript is regularly utilized together with Java. You ought to abstain from utilizing some Java objects furthermore, properties as JavaScript identifiers:

getClass java JavaArray javaClass JavaObject JavaPackage

Windows Reserved Words

JavaScript can be utilized outside HTML. It very well may be utilized as the programming language in numerous other applications.

In HTML you should (for convenientce you should) abstain from utilizing the name of HTML furthermore, Windows objects and properties:

alert all anchor anchors area
assign blur button checkbox clearInterval
clearTimeout clientInformation close closed confirm
constructor crypto decodeURI decodeURIComponent defaultStatus
document element elements embed embeds
encodeURI encodeURIComponent escape event fileUpload
focus form forms frame innerHeight
innerWidth layer layers link location
mimeTypes navigate navigator frames frameRate
hidden history image images offscreenBuffering
open opener option outerHeight outerWidth
packages pageXOffset pageYOffset parent parseFloat
parseInt password pkcs11 plugin prompt
propertyIsEnum radio reset screenX screenY
scroll secure select self setInterval
setTimeout status submit taint text
textarea top unescape untaint window

HTML Event Handlers

In expansion you ought to abstain from utilizing the name of all HTML occasion handlers.


onblur onclick onerror onfocus
onkeydown onkeypress onkeyup onmouseover
onload onmouseup onmousedown onsubmit