値 NaN (JavaScript)

[1]

The primitive value NaN represents the set of IEEE Standard "Not-a-Number" values. This value is a member of the Number type.

[2]

名前

NaN

型

Number

[3] XQuery 1.0 and XPath 2.0 Functions and Operators (Second Edition) ( (2010-12-17 00:06:54 +09:00 版)) http://www.w3.org/TR/2010/REC-xpath-functions-20101214/#numeric-types

nan, -nan (Perl)

[4]

$ perl -MPOSIX -MDevel::Peek -e 'print Devel::Peek::Dump POSIX::fmod(12,0)'
SV = NV(0x1c3cca8) at 0x1c2c780
  REFCNT = 1
  FLAGS = (PADTMP,NOK,pNOK)
  NV = -nan

[5] 文字列化すると Perl 5.22 では NaN ですが、 Perl 5.14 では nan でした。

[6] perl -MPOSIX -e 'print POSIX::fmod(12,0)' は Perl 5.14 では -nan、 5.22 では NaN になります。

[7] pack 'L', 0+'NaN' は 5.22 以降は例外を投げます。 以前は 0 扱いでした。

歴史

[8] Inline the infinite/NaN argument handling in 2d canvas methods (zcorpan著, 2016-09-30 22:38:34 +09:00) https://github.com/whatwg/html/commit/6f2c0e884e3a7974637514b04e62f7352b6e405d

[9] XQuery 3.1: An XML Query Language (2017-03-20 09:23:33 +09:00) https://www.w3.org/TR/2017/REC-xquery-31-20170321/#id-static-decimal-format-NaN

[10] XML Path Language (XPath) 3.1 (2017-03-20 09:18:04 +09:00) https://www.w3.org/TR/2017/REC-xpath-31-20170321/#id-static-decimal-format-NaN

[11] XPath and XQuery Functions and Operators 3.1 (2017-03-21 16:02:06 +09:00) https://www.w3.org/TR/2017/REC-xpath-functions-31-20170321/#op.numeric

[12] Clarify that unrestricted doubles and floats include NaNs. (#393) (tobie著, 2017-07-30 21:58:17 +09:00) https://github.com/heycam/webidl/commit/44d0f24f4ef6632bf49dcf1650ff0d3c64778943

[13] 29240 – Clarify whether NaN is allowed in float/double types (2017-07-31 12:02:32 +09:00) https://www.w3.org/Bugs/Public/show_bug.cgi?id=29240

[14] Clarify that unrestricted doubles and floats include NaNs. by tobie · Pull Request #393 · heycam/webidl (2017-07-31 12:02:39 +09:00) https://github.com/heycam/webidl/pull/393

[15] Do nothing for NaN in setTransform(transform)/addPath(b, transform) (zcorpan著, 2017-09-26 18:01:42 +09:00) https://github.com/whatwg/html/commit/5b19b37c6c6d12f0526afc258686206550ac415c

[16] Canvas 2d context setTransform() functionality is unclear when argument contains NaN · Issue #2845 · whatwg/html (2017-09-27 15:55:25 +09:00) https://github.com/whatwg/html/issues/2845

[17] Do nothing for NaN in setTransform(transform)/addPath(b, transform) by zcorpan · Pull Request #2975 · whatwg/html (2017-09-27 15:56:26 +09:00) https://github.com/whatwg/html/pull/2975

[20] JavaScript で CPU が Intel かどうかを判定する(ついでに JIT を検知する), 2023-01-11T02:41:12.000Z, 2023-01-12T02:48:45.103Z http://nmi.jp/2023-01-11-Detecting-Intel-Arch-in-JavaScript

[21] fingerprinting vector