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What are Reserved Keywords

JavaScript Reserve Keywords are the words that you cannot use as identifiers (variable names, function names, and loop labels) in your JavaScript programs.

Reserved Keywords in ECMAScript 5/6 (ES5/6)

abstract arguments await* 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 marked with* are new in ECMAScript 5 and 6.

Removed Reserved Keywords

The following reserved words has been removed from the ECMAScript 5/6 standard:

abstract boolean byte char double final float goto
int long native short synchronized throws transient volatile

JavaScript Objects, Properties, and Methods

You should also avoid using the name of JavaScript built-in objects, properties, and methods:

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

HTML Event Handlers

You should also avoid using the name of JavaScript built-in objects, properties, and methods:

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











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