[1] 
>A [DFN@en[primitive value]] is a [[member]] of one of the [[types]] [CODE(JS)@en[[[Undefined]]]], 
[CODE(JS)@en[[[Null]]]], [CODE(JS)@en[[[Boolean]]]], [CODE(JS)@en[[[Number]]]], or [CODE(JS)@en[[[String]]]].
A [[primitive value]] is a datum that is represented directly at the lowest level of the language implementation.


;; [CITE[ECMAScript Language Specification (HTML version)]] ([TIME[2009-04-03 04:43:48 +09:00]] 版) <http://bclary.com/2004/11/07/#a-4.3.2>