JavaScript 2.0-The Complete Reference, Second ... - freecodingtutorial

Generally speaking, reserved words are reserved from use because they already have a
defined meaning in some variant of JavaScript or a related technology. Reserved words
generally are categorized in three types:
Language keywords
Future reserved words
Words such as object names or related technology keywords
Table C-1 lists the words in the first two categories based upon the JavaScript 1.5 specification
combined with Microsoft‘s Jscript documentation.
Table C-1: Reserved Words in JavaScript 1.5
>abstract else instanceof switch
>boolean enum int synchronized
>break export interface this
byte extends long throw
case false native throws
catch final new transient
char finally null true
class float package try
const for private typeof
continue function protected val
debugger goto public var
default if return void
delete implements short volatile
do import static while
double in super with
Note Some reserved words related to types not found in JavaScript, like byte, are reserved in
some versions of ECMAScript and not others.
Beyond these well-known reserved words, there are other words that may have problems under
some versions of JavaScript including ECMAScript 4, Jscript.NET, and JavaScript 2.0. While
the words shown in Table C-2 may not actually be reserved in your browser, they should be
avoided just to be safe.
Table C-2: Potentially Reserved Words
As event Is uint
Assert get Namespace ulong
Decimal include Require use
Ensure internal Sbyte ushort
Exclude invariant Set
The third category of dangerous identifiers includes names of intrinsic JavaScript objects,
functions, and data types. Words like String, parseInt, document, and so on, are included in
this category. There are far too many of these ―dangerous‖ identifier names to list, but consider
anything in Appendix A or Appendix B to be a JavaScript identifier and inappropriate for other
use.