Programming Tutorials

List of Keywords and reverved words in Javascript

By: Emiley J.  

Keywords

By rule, keywords are reserved and cannot be used as variable or function names. Here is the complete list of JavaScript keywords:

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

If you use a keyword as a variable or function name, you will probably be greeted with an error message like this: “Identifier expected.”

Reserved Words

JavaScript also defines a number of reserved words. The reserved words are, in a sense, words that are reserved for future use as keywords. Because of this, reserved words cannot be used as variable or function names. The complete list of reserved words in ECMA-262 Edition 3 is as follows:

abstract
boolean
byte 
char 
class 
const 
debugger 
double 
enum
export 
extends 
final 
float 
goto 
int
interface
implements
import
long
native
package
private
protected
public
short
static
super
synchronized
throws
transient
volatile

If you use a reserved word as a variable or function name, more than likely you will not receive an error...until a future browser implements one of them. Then the word will be considered a keyword, and you will get a keyword error.