KEYWORDS AND RESERVED WORDS
ECMA-262 describes a set of reserved keywords that have specific uses, such as indicating the beginning or end of control statements or performing specific operations. By rule, keywords are reserved and cannot be used as identifiers or property names. The complete list of keywords for ECMA-262, sixth edition is as follows:
break do in typeof
case else instanceof var
catch export new void
class extends return while
const finally super with
continue for switch yield
debugger function this
default if throw
delete import try
The specification also describes a set of future reserved words that cannot be used as identifiers or property names. Though reserved words don't have any specific usage in the language, they are reserved for future use as keywords.
The following is the complete list of future reserved words defined in ECMA-262, sixth edition:
Always reserved...