* 用法

[5] [CODE(DOMi)@en[Event]] の[[構築子]]の[[引数]]や [CODE(DOMi)@en[DeviceRotationRateInit]]
の[[メンバー]]のように、
新しく作成する[[オブジェクト]]の各[[IDL属性]]が持つべき値を与えるために使うことがあります。

[6] [CODE(DOMm)@en[createElement]] や [CODE(DOMm)@en[addEventListener]] の[[引数]]のように、
[[名前付き引数]]として使うことがあります。

* 複製

[46] 
[[プッシュ購読の作成]]では[[辞書]]が複製されます。

* 歴史

[1] [CITE@en[Allow trailing position dictionary arguments to be not optional, if t… · heycam/webidl@b1dea26]] ([TIME[2015-06-01 17:43:57 +09:00]] 版) <https://github.com/heycam/webidl/commit/b1dea262d0d5894d8954fa6478e30bf67fc2950d>

[2] [CITE@en[Clarify that the order to get/set dictionary members is lexicographical. · heycam/webidl@00651ce]]
([TIME[2015-10-08 11:33:10 +09:00]] 版)
<https://github.com/heycam/webidl/commit/00651ceba183c979ef401846d408804597a9a588>

[3] [CITE@en[Remove support for '''['''Constructor''']''' on dictionaries (fixes #109).]]
( ([[Ms2ger]]著, [TIME[2016-04-20 20:34:07 +09:00]]))
<https://github.com/heycam/webidl/commit/1982dc3f17002c07f93b39e22f69846478e4a9e2>

[4] [CITE@en[20158 – Unrestricted typed dictionary]]
([TIME[2016-10-14 11:53:24 +09:00]])
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=20158>

[7] [CITE@en[Modernize and clean up dictionary type conversions]]
([[domenic]]著, [TIME[2016-11-11 04:25:09 +09:00]])
<https://github.com/heycam/webidl/commit/3bf3f84fe6b15634859f4e5080cc57881c2956d9>

[8] [CITE@en[Various follow-up fixes to #180. (#192)]]
([[tobie]]著, [TIME[2016-10-18 17:01:43 +09:00]])
<https://github.com/heycam/webidl/commit/40d03aad7d1bf137d62b59b074778f7c7d7e0cc4>

[9] [CITE@en[Simplify the distinguishable table (#183)]]
([[jyasskin]]著, [TIME[2017-01-21 07:47:51 +09:00]])
<https://github.com/heycam/webidl/commit/89fc3a36b076da2563cd4c22ff9a4ef7c0c9a2f6>

[10] [CITE@en[Ban nullable records in dictionary members and operation arguments. (#…]]
([[jyasskin]]著, [TIME[2017-02-04 03:48:40 +09:00]])
<https://github.com/heycam/webidl/commit/7259bd954df1f3d43f675cb71443d5dd200b5fec>

[11] [CITE@en[Fix #296: ban dictionary recursion through records. (#298)]]
([[jyasskin]]著, [TIME[2017-02-04 03:49:11 +09:00]])
<https://github.com/heycam/webidl/commit/662b008b5d20a56912835ceb47749157f6e91950>

[12] [CITE@en[Base sequences, dictionaries, and records on Infra types (#317)]]
([[domenic]]著, [TIME[2017-02-23 08:14:24 +09:00]])
<https://github.com/heycam/webidl/commit/26aa8308811da812d28a5b3dd06fabcefecb71f0>

[13] [CITE@en[Editorial: use less-confusing variable names in dictionary conversion (…]]
([[domenic]]著, [TIME[2018-07-04 06:57:23 +09:00]])
<https://github.com/heycam/webidl/commit/ebdaa2b152fe550cf6a709a7ab303cd3c4df7320>

[14] [CITE@en[Editorial: use less-confusing variable names in dictionary conversion by domenic · Pull Request #570 · heycam/webidl]]
([TIME[2018-07-04 21:52:45 +09:00]])
<https://github.com/heycam/webidl/pull/570>

[15] [CITE@en[A dictionary inheriting from a non-JSON type can't be a JSON type. (#571]]
([[bzbarsky]]著, [TIME[2018-07-18 00:26:11 +09:00]])
<https://github.com/heycam/webidl/commit/d3b317273c6e8b184ad6023ac145cf25c933a50e>

[16] [CITE@en[Is a dictionary which has an inherited dictionary with a non-JSON-type member a JSON type? · Issue #555 · heycam/webidl]]
([TIME[2018-07-18 15:27:59 +09:00]])
<https://github.com/heycam/webidl/issues/555>

[17] [CITE@en[A dictionary inheriting from a non-JSON type can't be a JSON type. by bzbarsky · Pull Request #571 · heycam/webidl]]
([TIME[2018-07-18 15:28:21 +09:00]])
<https://github.com/heycam/webidl/pull/571>

[18] [CITE@en[Use map/exists to define dictionary/present. (#610)]]
([[Ms2ger]]著, [TIME[2019-01-15 02:11:26 +09:00]])
<https://github.com/heycam/webidl/commit/d05c8ccf0c022737018b2f6312a05d280dd79fbe>

[19] [CITE@en[Dictionary members' "present" definition seems circular · Issue #381 · heycam/webidl]]
([TIME[2019-06-01 11:47:31 +09:00]])
<https://github.com/heycam/webidl/issues/381>

[20] [CITE@en[Use map/exists to define dictionary/present. by Ms2ger · Pull Request #610 · heycam/webidl]]
([TIME[2019-06-01 11:47:45 +09:00]])
<https://github.com/heycam/webidl/pull/610>

[21] [CITE@en[Define a way to specify a default value for dictionaries (the literal…]]
([[bzbarsky]]著, [TIME[2019-07-02 01:34:11 +09:00]])
<https://github.com/heycam/webidl/commit/7329e8c62b5825376a52626a579a1890ac83cb29>

[22] [CITE@en[Define a way to specify a default value for dictionaries (the literal "{}") and require it to be specified for the dictionary arguments that are required to be optional. by bzbarsky · Pull Request #750 · heycam/webidl]]
([TIME[2020-01-12 15:15:13 +09:00]])
<https://github.com/heycam/webidl/pull/750>

[23] [CITE@en[Is it true that dictionaries can't have a default value specified? · Issue #585 · heycam/webidl]]
([TIME[2020-01-12 15:18:22 +09:00]])
<https://github.com/heycam/webidl/issues/585>

[24] [CITE@en[Consider requiring optional dictionary defaulting explicitly · Issue #602 · heycam/webidl]]
([TIME[2020-01-12 15:18:42 +09:00]])
<https://github.com/heycam/webidl/issues/602>

[25] [CITE@en[Align with IDL dictionary changes by annevk · Pull Request #771 · whatwg/dom]]
([TIME[2020-01-12 16:42:24 +09:00]])
<https://github.com/whatwg/dom/pull/771>

[26] [CITE@en[Align with IDL dictionary changes]]
([[annevk]]著, [TIME[2019-08-09 17:16:55 +09:00]])
<https://github.com/whatwg/html/commit/1224105b63d1f2ba33aecc3ebd8a908335377ff4>

[27] [CITE@en[Align with IDL dictionary changes by annevk · Pull Request #4745 · whatwg/html]]
([TIME[2020-01-12 16:43:37 +09:00]])
<https://github.com/whatwg/html/pull/4745>

[28] [CITE@en[Align with IDL dictionary changes]]
([[annevk]]著, [TIME[2019-08-09 17:31:23 +09:00]])
<https://github.com/whatwg/fetch/commit/60a516da3c3c023da74a151d0970fdcb4735d94e>

[29] [CITE@en[Align with IDL dictionary changes by annevk · Pull Request #919 · whatwg/fetch]]
([TIME[2020-01-12 16:44:11 +09:00]])
<https://github.com/whatwg/fetch/pull/919>

[30] [CITE@en[Align with IDL dictionary changes]]
([[annevk]]著, [TIME[2019-08-09 17:50:34 +09:00]])
<https://github.com/whatwg/notifications/commit/588e3fec26631fbc897985539a49d7f8a45f5b74>

[31] [CITE@en[Align with IDL dictionary changes by annevk · Pull Request #149 · whatwg/notifications]]
([TIME[2020-01-12 16:44:37 +09:00]])
<https://github.com/whatwg/notifications/pull/149>

[32] [CITE@en[Align with IDL dictionary changes]]
([[annevk]]著, [TIME[2019-08-09 17:28:39 +09:00]])
<https://github.com/whatwg/encoding/commit/8abcdafc111f07200170a31073e938bfe83cdd21>

[33] [CITE@en[Align with IDL dictionary changes by annevk · Pull Request #181 · whatwg/encoding]]
([TIME[2020-01-12 16:44:56 +09:00]])
<https://github.com/whatwg/encoding/pull/181>

[34] [CITE@en[Set default value of optional dictionary to {} (#1448)]]
([[CYBAI]]著, [TIME[2019-08-09 19:49:06 +09:00]])
<https://github.com/w3c/ServiceWorker/commit/78fad94c88bb569703138ce3f592e7ac6b2bf64e>

[35] [CITE@en[Set default value of optional dictionary to {} by CYBAI · Pull Request #1448 · w3c/ServiceWorker]]
([TIME[2020-01-12 16:45:18 +09:00]])
<https://github.com/w3c/ServiceWorker/pull/1448>

[36] [CITE@en[Align with IDL dictionary changes]]
([[annevk]]著, [TIME[2019-08-09 17:23:42 +09:00]])
<https://github.com/whatwg/xhr/commit/d1c80f186f771b2313c2adecad4f68b7e7c0915d>

[37] [CITE@en[Align with IDL dictionary changes by annevk · Pull Request #250 · whatwg/xhr]]
([TIME[2020-01-12 16:46:31 +09:00]])
<https://github.com/whatwg/xhr/pull/250>

[38] [CITE@en[Add explicit '''['''Exposed''']''' + dictionary default value (#407)]]
([[saschanaz]]著, [TIME[2019-08-22 20:36:08 +09:00]])
<https://github.com/w3c/webappsec-csp/commit/90a9bc886234d056286f84dd6c9fb0c482fd460f>

[39] [CITE@en[Add explicit '''['''Exposed''']''' + dictionary default value by saschanaz · Pull Request #407 · w3c/webappsec-csp]]
([TIME[2020-01-12 16:51:57 +09:00]])
<https://github.com/w3c/webappsec-csp/pull/407>

[40] [CITE@en[Add dictionary default value (#292)]]
([[saschanaz]]著, [TIME[2019-08-28 01:18:21 +09:00]])
<https://github.com/w3c/IndexedDB/commit/24f51a8eabf9e42cc9699d2179d34984ba6ea9fb>

[41] [CITE@en[Update to Web IDL changes to optional dictionary defaulting · Issue #285 · w3c/IndexedDB]]
([TIME[2020-01-12 17:02:07 +09:00]])
<https://github.com/w3c/IndexedDB/issues/285>

[42] [CITE@en[Add dictionary default value by saschanaz · Pull Request #292 · w3c/IndexedDB]]
([TIME[2020-01-12 17:02:29 +09:00]])
<https://github.com/w3c/IndexedDB/pull/292>

[43] [CITE@en[Add empty dictionary default value for requestFullscreen (#158)]]
([[foolip]]著, [TIME[2019-09-26 18:16:55 +09:00]])
<https://github.com/whatwg/fullscreen/commit/20ea24b98e23f28465ff3fb71ee4ea7a329be76e>

[44] [CITE@en['''['''fullscreen''']''' Align with Web IDL specification by autokagami · Pull Request #157 · whatwg/fullscreen]]
([TIME[2020-02-01 14:46:17 +09:00]])
<https://github.com/whatwg/fullscreen/pull/157>

[45] [CITE@en[Add empty dictionary default value for requestFullscreen by foolip · Pull Request #158 · whatwg/fullscreen]]
([TIME[2020-02-01 14:46:31 +09:00]])
<https://github.com/whatwg/fullscreen/pull/158>