JavaScript keywords and reserved words

ECMA-262 defines a set of keywords (keyword) supported by ECMAScript.

These keywords identify the beginning and/or end of the ECMAScript statement. By regulation, keywords are reserved and cannot be used as variable names or function names.

The following is a complete list of ECMAScript keywords:

Break
Case
Catch
Continue
Default
Delete
Do
Else
Finally
For
function
If
Inch
instanceof
New
Return
Switch
This
Throw
Try
typeof
Var
void
While
With

Reserved words are words that are reserved for future keywords in some sense. Therefore, reserved words cannot be used as variable names or function names.

The complete list of reserved words is as follows:

Abstract
Boolean
Byte
Char
Class
Const
Debugger
Double
Enum
Export
Extends
Final
Float
Goto
Implements
Import
Int
Interface
Long
Native
Package
Private
Protected
Public
Short
Static
Super
Synchronized
Throws
Transient
Volatile

It is important to note that when defining variables, do not use the name of the system keyword or reserved word, otherwise there will be some inexplicable error!

JavaScript keywords and reserved words