Reliable JavaScript Certification Online #

Keywords have special use in JavaScript and cannot be used as identifiers. Below the list of JavaScript keywords:

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

Outside the keywords JavaScript defines reserved keywords which do not have special functionality now, but these may be used as future keywords. It should be noted that there are several different situations when these words are reserved.

a) Always reserved:

enum

b) Reserved in strict mode:

implements
interface
let
package
private
protected
public
static

c) Reserved in module code:

await

d) Reserved words in older specifications:

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

Additionally literals that cannot be used as identifiers:

null
true
false