JavaScript note 3--identifiers and reserved words

1. Identifiers
JavaScript identifiers must begin with a letter, an underscore (_), or a dollar sign ($). Subsequent characters can be letters/numbers/underscores/dollar signs. You can also use non-English language or mathematical symbols to write identifiers;

2. Reserved words
break/delete/function/return/typeof/case/do/if/switch/var/catch/else/in/this/void/continue/false/instanceof/ throw/while/debugger/finally/
New/true/with/default/for/null/try

3.ECMASCRIPT5 retains the following keywords:
Class/const/enum/export/extends/import/super

4. Keywords in strict mode:
Implements/let/private/public/yield/interface/package/protected/static/arguments/eval

5.ECMASCRIPTS3 retains the following keywords:
abstract/double/goto/native/static/boolean/enum/implements/package/super/byte/export/import/private/ synchronized/char/extends/int/protected/throws/class/final/interface/public/transient/const/float/long/short/ Volatile

6. Predefined global variables and function names should be avoided by using the identifiers as their own:
Arguments/encodeuri/infinity/number/regexp/array/encodeuricomponent/isfinite/object/string/boolean/error/isnan /parsefloat/syntaxerror/date/eval/json/parseint/typeerror/decodeuri/evalerror/math/rangeerror/undefined/ Decodeuricomponent/function/nan/referenceerror/urierror

JavaScript note 3--identifiers and reserved words