JavaScript Keywords

In JavaScript, a keyword is a reserved word define by the JavaScript developer, with its pre-defined meaning. For example:

HTML with JavaScript Code

<!DOCTYPE html>
<html>
<body>
   
   <script>
      var x = 10;
      if(x == 0) {
         document.write("The value of 'x' is equal to 0.")
      }
      else if(x > 0) {
         document.write("The value of 'x' is a positive number.");
      }
      else {
         document.write("The value of 'x' is a negative number.");
      }
   </script>
   
</body>
</html>

Output

In above example, the var, if, and else are keywords. The var is used to declare a variable. The if is used when we need to execute some block of code, when the specified condition evaluates to be true. The else is the counter-part of if.

Note - Do not use any keyword as an identifier. If you do so, then that word acts the way, it is defined by the developer. So avoid using any keyword listed in this article.

List of All Keywords in JavaScript

Here are the list of all keywords available in JavaScript:

alert
anchor
anchors
area
arguments
array
assign
await
blur
break
button
case
catch
checkbox
class
clearinterval
cleartimeout
clientinformation
close
closed
confirm
const
constructor
continue
crypto
date
debugger
decodeuri
decodeuricomponent
default
defaultstatus
delete
do
document
element
elements
else
embed
embeds
encodeuri
encodeuricomponent
enum
escape
eval
eval
event
export
extends
false
fileupload
finally
focus
for
form
forms
frame
framerate
frames
function
function
getclass
hasownproperty
hidden
history
if
image
images
implements
import
in
infinity
innerheight
innerwidth
instanceof
interface
isfinite
isnan
isprototypeof
java
javaarray
javaclass
javaobject
javapackage
layer
layers
length
let
link
location
math
mimetypes
name
nan
navigate
navigator
new
null
number
object
offscreenbuffering
onblur
onclick
onerror
onfocus
onkeydown
onkeypress
onkeyup
onmouseover
onload
onmouseup
onmousedown
onsubmit
open
opener
option
outerheight
outerwidth
package
packages
pagexoffset
pageyoffset
parent
parsefloat
parseint
password
pkcs11
plugin
private
prompt
propertyisenum
protected
prototype
public
radio
reset
return
screenx
screeny
scroll
secure
select
self
setinterval
settimeout
static
status
string
submit
super
switch
taint
text
textarea
this
throw
top
tostring
true
try
typeof
undefined
unescape
untaint
valueof
var
void
while
window
with
yield

JavaScript Online Test

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