CoffeeScript in Action (2014)
Appendix A. Reserved words
The CoffeeScript compiler maintains a list of reserved words that will break compilation if you use them as variable names in a program.
For CoffeeScript 1.6.3 the reserved words list appears in table A.1.
Table A.1. CoffeeScript compiler 1.6.3 reserved words
|
case default function var void with const let enum export import native __hasProp __extends __slice __bind __indexOf |
implements interface package private protected public static yield true false null this new delete typeof in arguments eval |
instanceof return throw break continue debugger if else switch for while do try catch finally class extends |
super undefined then unless until loop of by when and or is isnt not yes no on off |
Some of the reserved words in CoffeeScript are reserved because the compiler uses them in the generated JavaScript. Others are reserved because they’re reserved words in the ECMAScript specification, as shown in tables A.2 and A.3.
Table A.2. Reserved words in the fifth edition of the ECMAScript specification
|
break do instanceof typeof case else try |
return void continue for switch while this |
with default if throw delete in |
new var catch finally debugger function |
There are some words that are reserved for future editions of the ECMAScript specification, as shown in table A.3. Some of them, such as class, also have meaning in CoffeeScript. Don’t use them as identifiers.
Table A.3. Words reserved for future editions of the ECMAScript specification
|
class enum extends super |
export import implements let |
interface package protected static |
private public const yield |
There are some built-in constructors that you should treat as reserved. If you redefine them, you’ll most likely break your programs:
Object, Function, Array, String, Boolean, Number, Date, RegExp, Error, EvalError, RangeError, ReferenceError, SyntaxError, TypeError, URIError
There are other global objects and value properties that you’ve encountered:
Math, JSON, Infinity, NaN
Finally, there are some global functions:
eval, parseInt, parseFloat, isNaN, isFinite, decodeURI, decodeURIComponent, encodeURI, encodeURIComponent