* 型 [CODE(JS)@en[Boolean]]、ブール値 (JavaScript)

[4] 
>    A [DFN@en[boolean value]] is a [[member]] of the [[type]] [DFN@en[[[Boolean]]]]
and is one of two unique [[values]], [CODE(JS)@en[[[true]]]] and [CODE(JS)@en[[[false]]]].

;;[CITE[ECMAScript Language Specification (HTML version)]] ([TIME[2009-04-03 04:43:48 +09:00]] 版) <http://bclary.com/2004/11/07/#a-4.3.13>

[5] 
> The [[type]] [DFN@en[[CODE(JS)@en[Boolean]]]] represents a logical entity and consists of exactly two unique [[values]].
One is called [CODE(JS)@en[[[true]]]] and the other is called [CODE(JS)@en[[[false]]]].

;; [CITE[ECMAScript Language Specification (HTML version)]] ([TIME[2009-04-03 04:43:48 +09:00]] 版) <http://bclary.com/2004/11/07/#a-4.3.14>

* [CODE(JS)@en[Boolean]] オブジェクト (JavaScript)

[6] 
>A [DFN@en[Boolean object]] is a [[member]] of the [[type]] [CODE(JS)@en[[[Object]]]] and is an
[[instance]] of the [[built-in]] [CODE(JS)@en[[[Boolean]]]] [[object]]. That is, a [[Boolean object]]
is created by using the [CODE(JS)@en[[[Boolean]]]] [[constructor]] in a [CODE(JS)@en[[[new]]]] [[expression]],
supplying a [[boolean]] as an [[argument]]. The resulting [[object]] has an implicit (unnamed) [[property]]
that is the [[boolean]]. A [[Boolean object]] can be coerced to a [[boolean value]].

;;
[CITE[ECMAScript Language Specification (HTML version)]] ([TIME[2009-04-03 04:43:48 +09:00]] 版) <http://bclary.com/2004/11/07/#a-4.3.15>

* メモ

[7] [CITE@en[Bug 28477 – Warn against boolean arguments defaulting to true]]
([TIME[2015-04-14 12:39:48 +09:00]] 版)
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=28477>

[8] [CITE@en[Write structured clone algorithm in terms of ECMAScript · whatwg/html@bfb960c]]
([TIME[2016-03-02 16:44:53 +09:00]] 版)
<https://github.com/whatwg/html/commit/bfb960c938580c95e77365e614218b952f96375b>

[1] [CITE@en[Breaking: refactor structured clone into serialize/deserialize]]
([[domenic]]著, [TIME[2017-03-21 06:09:33 +09:00]])
<https://github.com/whatwg/html/commit/97d644c97335956610a31e8ad98d1a388c063e84>