JavaScript Reserved Words and Keywords

The keywords below are used by JavaScript for particular purposes, and should not be used as the names of variables, functions, objects, properties, methods, or arrays:

break
case
catch
continue
debugger
default
delete
do
else
finally
for
function
if
in
instanceof
new
return
switch
this
throw
try
typeof
var
void
while
with

Additional Reserved Words

The reserved words below may be used as keywords by JavaScript at a later date and should not be used as the names of variables, functions, objects, properties, methods, or arrays:

abstract
boolean
byte
char

class
const
double
enum
export
extends
final
float
goto
implements
import
int
interface
let
long
native
package
private
protected
public
short
static
super
synchronized
throws
transient
volatile
yield

Additional Notes

If you run JavaScript code in strict mode, then the keywords arguments and eval will need to be added to the list of reserved words.