JavaScript documentation status

This page tries to track ongoing documentation work in the MDN JavaScript section. Feel free to contribute!

Summary

Pages	No tags	Needs* tags	Missing tags	Editorial reviews	Technical reviews	Outdated pages	Dev-doc-needed bugs	Documentation requests
807	0 (0%)	0 (0%)	0 (0%)	0 (0%)	1 (1%)	14 (2%)	6 (1%)	17 (3%)

See also localization status of this section.

Technical reviews

Found 1 pages. Learn more about how to do a technical review.

Array.prototype.reduce()

Outdated pages

Found 14 pages. These pages haven't been updated in over a year. Outdated pages can have problems with both content and format. Look at these pages and consider: Is this page talking about the Web of today? Does it look consistent with newer pages in this topic area? If not, make any needed changes.

Index
399 days old
Meta programming
377 days old
Function.caller
421 days old
Object.prototype.__count__
471 days old
Object.prototype.__parent__
470 days old
Object.prototype.eval()
470 days old
ParallelArray
470 days old
RegExp.input ($_)
468 days old
RegExp.lastMatch ($&)
468 days old
RegExp.lastParen ($+)
468 days old
RegExp.leftContext ($`)
468 days old
StopIteration
462 days old
JavaScript technologies overview
374 days old
New in JavaScript 1.7
366 days old

Dev-doc-needed bugs

Found 6 bugs. Learn more about how to resolve a dev-doc-needed bug.

Bug	Summary	Release
1204024	Duplicate __proto__ property in destructuring form throws SyntaxError	mozilla52
1243858	Exponentiation Operator precendence update (ES2016/ES7, Stage 4)	mozilla52
1041341	Make `[...rest,] = []` a SyntaxError	mozilla52
1130636	Reimplement Array.prototype.toLocaleString as per ECMA-402 Edition 2.0 (Intl)	mozilla52
1243717	Support destructuring for rest parameters	mozilla52
1122396	Make %TypedArray%.of and %TypedArray%.from non-generic methods	mozilla52

Browse as bug list.

Documentation requests

Found 17 bugs. Documentation request bugs can contain various kinds work related to MDN pages. Read through the bug and ask questions in the bug if in doubt.

Bug	Summary
1179881	Write a JS error reference
1201380	Examples and text don't match up in "details of the object model" page
1204224	Unclear explanation in "Working With Objects" tutorial
1243496	The function declaration and function expression documentation is incorrect
1245977	MathML fallback: square root is not displayed correctly
1275816	Explain how \|this\| value is calculated in call expression, and the difference between `foo[prop]()` and `func = foo[prop], func()`
1281244	the "window.open" documentation is outdated
1281696	iterating with let in for-loops
1286628	Object.prototype.constructor is not a reference to the constructor of the prototype
1294338	charCodeAt and codePointAt in String documentation seem almost backwards
1294635	Polyfills from site are not working properly in IE11
1301501	polyfill uses != to check typeof assign to "function" vs !==
1303603	Clarify that RegExp.prototype.exec() returns a special array
1305261	Async Functions/Await Documentation
1307755	Given for..of example needs some explanation, not self-explaining
1308151	Object spread not documented
1309784	Add Cyclomatic Complexity

Browse as bug list.

Localizations

Please help us to localize this documentation into different languages. Read more about how to translate.

Language	Pages	Translated	Translations up to date
af	804	0 (0%)	0 (0%)
bn-BD	804	32 (3%)	0 (0%)
ca	804	320 (39%)	9 (2%)
de	804	355 (44%)	243 (68%)
es	804	312 (38%)	37 (11%)
fa	804	9 (1%)	1 (11%)
fr	807	807 (100%)	798 (98%)
id	804	82 (10%)	20 (24%)
it	804	77 (9%)	7 (9%)
ja	804	774 (96%)	163 (21%)
ko	804	264 (32%)	102 (38%)
nl	804	34 (4%)	2 (5%)
pl	804	261 (32%)	4 (1%)
pt-BR	804	256 (31%)	47 (18%)
pt-PT	804	30 (3%)	3 (10%)
ro	804	14 (1%)	0 (0%)
ru	807	502 (62%)	73 (14%)
zh-CN	804	527 (65%)	131 (24%)
zh-TW	804	86 (10%)	45 (52%)

Structure of the MDN JavaScript docs

Chapters of the MDN JavaScript section and their status
#	Chapter	Pages	Priority	Notes
0	Value & function properties in the global scope	16	1	Complete.
1	Object	40	1	Complete.
2	Function	14	1	Complete.
3	Array	38	1	Complete.
4	String	50	1	Complete.
5	Boolean	5	1	Complete.
6	Number	24	1	Complete.
7	Math	44	1	Complete.
8	Date	53	1	Complete.
9	RegExp	21	1	Complete.
10	Error EvalError InternalError RangeError ReferenceError SyntaxError TypeError URIError	24	4	Complete.
11	JSON	3	1	Complete.
12	Intl Intl.Collator Intl.DateTimeFormat Intl.NumberFormat	16	2	Complete.
13	Map	13	2	Complete.
14	WeakMap	7	2	Complete.
15	Set	11	2	Complete.
16	SIMD Float32x4 Float64x2 Int8x16 Int16x8 Int32x4 Uint8x16 Uint16x8 Uint32x4 Bool8x16 Bool16x8 Bool32x4 Bool64x2 SIMD types		3	In Nightly. Spec in flux.
17	WeakSet	6	2	Complete.
18	Proxy	17	3	Complete.
19	Reflect	15	3	Complete.
20	Generator (legacy and ES6) Iterator StopIteration GeneratorFunction	8	2	Complete.
21	`ArrayBuffer` (6) `DataView` (21) `TypedArray` (34 [+ 3]) `Float32Array` `Float64Array` `Int16Array` `Int32Array` `Int8Array` `Uint16Array` `Uint32Array` `Uint8Array` `Uint8ClampedArray`	73	2	Missing pages: 2 standard Array methods not yet implemented for TypedArrays (tracking bug 1071668).
22	Promise	8	1	Complete.
23	Symbol	9	2	Missing pages: Well-known symbols Symbol.hasInstance Symbol.isConcatSpreadable Symbol.replace Symbol.search Symbol.split Symbol.unscopables
24	ParallelArray	1	5	Complete.
25	Atomics SharedArrayBuffer	17	4	Preffed off. Spec in flux.
26	Expressions & Operators	29	1	Complete.
27	Statements & Declarations	27	1	Complete.
28	Functions	11	1	Complete.
29	Classes	4	1	Complete.
30	JavaScript Guide	15	1	Introduction Grammar and types Control flow and error handling Loops and iteration Functions Expressions and operators Numbers and dates Text formatting Regular Expressions Indexed collections Keyed collections Working with objects Details of the object model Iterators and generators Meta programming
31	New in JavaScript	15	4	Complete.
32	JavaScript error reference	36	3	Explains error messages (v8, Chakra). So that people searching for errors will find guidance.
33	Articles/Tutorials/Misc	17	3	Introductory: JavaScript technologies overview Introduction to Object-Oriented JavaScript Intermediate: A re-introduction to JavaScript (JS Tutorial) JavaScript data types and data structures Equality comparisons and sameness Closures Advanced: Inheritance and the prototype chain Strict mode Transitioning to strict mode JavaScript typed arrays Memory Management Misc reference: Enumerability and ownership of properties Iteration protocols Deprecated and obsolete features The legacy Iterator protocol Template Strings JavaScript shells Lexical grammar
34	Meta pages	9	4	Standard built-in objects JavaScript reference About this Reference JavaScript Language Resources Index About JavaScript JavaScript JavaScript methods index JavaScript properties index

Other tasks to do

Go through Firefox release notes for developers and site compat notes and make sure JS changes are documented properly in the references.
Make sure our compat tables are up to date by also going trough bug trackers of other open source browsers (e.g. WebKit, Blink)
Write a changelog for Chrome JavaScript releases like we have for Firefox. Same for other browsers/node.js?
Meta article about how to document in the JS MDN area.

Tagging standard

Pages in the JavaScript/ page tree should at least have the tag "JavaScript".
For methods belonging to an object, the name of the Object should be added (e.g. String.fromCharCode should have "String").
Methods should have "Method" and properties need a "Property" tag. All prototype members have the "prototype" tag.
Features added in a new ECMAScript version have the tags "ECMAScript6" and "ECMAScript 2015" or later versions/years.
The Experimental tag should only be used with new features where the standard in not yet finalized (e.g. in a strawman proposal) and the feature is in a Nightly version or behind a preference.
Features are Deprecated if their usage is discouraged and are Obsolete if they have been removed from engines.
If pages need any type of work, a "Needs*" tag should be added (see above).

Specifications

The following specifications are taken under consideration for this project:

Specification	Status
ECMAScript 5.1 (ECMA-262)	Standard
ECMAScript 2015 (6th Edition, ECMA-262)	Standard
ECMAScript 2017 Draft (ECMA-262)	Draft
ECMAScript Internationalization API 1.0 (ECMA-402)	Standard
ECMAScript Internationalization API 2.0 (ECMA-402)	Standard
ECMAScript Internationalization API 4.0 (ECMA-402)	Draft
SIMD	Draft
ECMAScript Shared Memory and Atomics	Draft
Proposals (with advanced stage and at least 1 implementation)	Draft

Help the 'JavaScript' documentation project…

Topic driver : Florian Scholz (IRC nickname: fscholz)

Look at the current status of the 'JavaScript' documentation.

Don't hesitate to contact us on #mdn or on the dev-mdc mailing-list: