# Reserved Words

# Overview

This article lists keywords that may not be used as variables, functions, methods, or object identifiers, because either Titanium or another source specifies its usage.

# ECMAScript Specification

The following keywords cannot be used as identifiers according to the ECMAScript Language Specification:

abstract boolean break byte case catch char class const continue debugger default delete do double else enum export extends finally	for function goto if implements import in instanceof int interface let long native new package private protected public return short	static super switch synchronized this throw throws transient try typeof with while var void volatile yield

# iOS

The following keywords are exposed to JavaScript from Objective C and may not be used as identifiers:

• _configure

• _destroy

• _initProperties

• autorelease

• deadlock

• dealloc

• description

• id

• init

• release

• startup

# Alloy

Do not use double underscore prefixes on variables, properties, or function names (e.g., __foo). They are reserved for use in Alloy.