Javascript Reserved Words.

gistfile1.txt

Reserved keywords as of ECMAScript 6

break
case
class
catch
const
continue
debugger
default
delete
do
else
export
extends
finally
for
function
if
import
in
instanceof
let
new
return
super
switch
this
throw
try
typeof
var
void
while
with
yield
Future reserved keywords

The following are reserved as future keywords by the ECMAScript specification. They have no special functionality at present, but they might at some future time, so they cannot be used as identifiers. These keywords may not be used in either strict or non-strict mode.

enum
await
The following are reserved as future keywords when they are found in strict mode code:

implements
package
protected
static
interface
private
public
Future reserved keywords in older standards

The following are reserved as future keywords by older ECMAScript specifications (ECMAScript 1 till 3).

abstract
boolean
byte
char
double
final
float
goto
int
long
native
short
synchronized
transient
volatile
Additionally, the literals null, true, and false are reserved in ECMAScript for their normal uses.

Reserved word usage

Reserved words actually only apply to Identifiers (vs. IdentifierNames) . As described in es5.github.com/#A.1, these are all IdentifierNames which do not exclude ReservedWords.