What’s new in JScript for IE8

Anith » What???s new in JScript for IE8

Anith » What???s new in JScript for IE8 — Wed, 25 Mar 2009 04:01:27 GMT

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re: What’s new in JScript for IE8

object does not support property or method — Wed, 25 Mar 2009 06:01:42 GMT

any chance this error:

object does not support property or method

will ever be fixed to something remotely meaningful?

e.g. TELL us WHICH property or method? or WHAT object we were trying to set stuff on.

What’s new in JScript for IE8

JScript Blog — Wed, 25 Mar 2009 06:02:03 GMT

During Beta1 and Beta2 pre-releases of IE8, we’ve blogged about the performance optimizations done in

re: What’s new in JScript for IE8

Joe — Wed, 25 Mar 2009 09:55:40 GMT

I really hope they've properly fixed the "Operation Aborted" error and will go back and fix it on IE6 and IE7 too.

re: What’s new in JScript for IE8

Brian LePore — Wed, 25 Mar 2009 16:10:48 GMT

Will JScript 5.8 be backported to IE7 just as Jscript 5.7 was backported to IE6 (I believe with this was with SP3)?

re: What’s new in JScript for IE8

someone — Wed, 25 Mar 2009 18:13:41 GMT

But on XPSP3, CScript after installing IE8 reports version 5.7 but Windows 7 CScript reports 5.8. Why the inferior treatment to XP WSH JScript?

re: What’s new in JScript for IE8

Jeffrey Gilbert — Wed, 25 Mar 2009 18:57:28 GMT

Stop blogging and go make IE9.

re: What’s new in JScript for IE8

Brad — Wed, 25 Mar 2009 19:07:43 GMT

And the damn thing is still showing the amazingly non-useful error location of line 1, char 132, which is the doctype declaration. still FAIL.

re: What’s new in JScript for IE8

David Owens — Thu, 26 Mar 2009 00:29:33 GMT

The JScript engine now exposes new language features only when the layout (document) mode is set to “IE8 Standards Mode.”

So, once again, the default for IE8 is for it to not work properly, unless I explicitly tell it to work properly.

Will IE9 default to the IE7 JavaScript feature set too?

re: What’s new in JScript for IE8

GauravS — Thu, 26 Mar 2009 00:52:01 GMT

@Brian LePore: As of now, there are no plans to back port JScript 5.8 to IE7.

@someone: Cscript.exe is not shipped as a part of IE8 but as a part of the Windows OS release. JScript.dll is shipped as a part of both - IE8 and the Windows OS release. So installing IE8 on a machine would upgrade the JScript.dll to version 5.8, but not change the version of Cscript.exe. On the other hand, Win7 ships the incremental version for CScript.exe, which is 5.8 (XPSP3 and Windows Vista shipped v5.7). Win 7 will also ship IE8 and version 5.8 of the JScript.dll. Hence there is no inferior treatment for CScript.

GauravS[MSFT]

re: What’s new in JScript for IE8

John Booze — Thu, 26 Mar 2009 02:25:25 GMT

I'd like to see javascript to start and stop profiles. This would improve reproducibility when doing performance investigations.

I would suggest staying consistent with FireBug:

console.profile()

console.profileEnd()

re: What’s new in JScript for IE8

PatriotB — Thu, 26 Mar 2009 10:59:05 GMT

@David: pages with strict-mode doctypes will default to IE8 standards mode so they automatically will get these script improvements. He's NOT saying you need to explicitly use the meta tag (opt-in) to get them.

@Jeffrey: I'm sure there's many other IE team members who are doing just that.

re: What’s new in JScript for IE8

GauravS — Thu, 26 Mar 2009 21:36:54 GMT

@David Owens: I am not sure if I understood this correctly. The default for IE8 will work properly. Let me try to explain this with an example. If a page uses “IE8 Standards” mode, the new JScript features like native JSON support will be enabled. However, if a user already uses some proprietary JSON implementation, which is broken due to the new native JSON support, a user can switch to using a non “IE8 standards” mode till the time he changes the code and starts taking advantage of the native JSON support. This will help a site owner maintain the end user experience and compatibility with IE7. We will post more details around the versioning of JScript features in a follow-up post. Let me know if this still does not address your concern.

@ John Booze: Thanks for your feedback. We will consider this for the future release.

re: What’s new in JScript for IE8

Andy Earnshaw — Fri, 27 Mar 2009 00:56:33 GMT

The improvements to Javascript are very welcome. I know I should have thought of this sooner, but I'd really like to be able to access the debugging tools for a Windows Sidebar Gadget.

Maybe someone from the IE team could have a brew with someone from the Sidebar team and work something out before Windows 7 Gold?

re: What’s new in JScript for IE8

Andy Earnshaw — Fri, 27 Mar 2009 00:57:56 GMT

Sorry, I totally meant JScript. Same difference, right? Just kidding!

re: What’s new in JScript for IE8

Tino Zijdel — Sat, 28 Mar 2009 02:47:42 GMT

2 small requests that would make JScript a lot more compatible with JavaScript:

alert('foo'[2]) - should give 'o' iso 'undefined'

alert('foo'.substr(-2)) should give 'oo' iso 'foo'

re: What’s new in JScript for IE8

Dan — Sat, 28 Mar 2009 03:07:57 GMT

Tino, I'm not sure I understand your first point... IE8, Firefox3, Chrome, and Safari 4 all give the same result here.

For the second point, per the ECMAScript 3.1 specification and Mozilla's documentation (developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/String/substring) when passing a negative subscript argument to substring() it is supposed to be turned into 0. ("If either argument is less than 0 or is NaN, it is treated as if it were 0.")

Hence, if /other/ browsers wanted to be more compatible with ECMAScript, they should probably behave more like IE.

re: What’s new in JScript for IE8

GauravS — Tue, 31 Mar 2009 00:01:09 GMT

@Tino: Thanks for your feedback. The first issue has been fixed in IE8. However, being a breaking change, the support for the same is available only when you launch the JScript engine in v5.8 mode i.e. in the “Internet Explorer 8 Standards”. You could read more about how to choose the layout mode here - http://msdn.microsoft.com/en-us/library/cc288325(VS.85).aspx. We will take a look at the second deviation that you pointed out for the next release.

GauravS[MSFT]

re: What’s new in JScript for IE8

James Reinke — Thu, 02 Apr 2009 22:52:32 GMT

GauravS:

Will IE8 browsers running in the IE7 Standards Document Mode benefit from the new JScript performance gains or will they be limited to the IE7 JScript performance? Thanks in advance for your time.

IE8 における Jscript の変更点

Windows 開発統括部 Blog — Fri, 03 Apr 2009 14:21:30 GMT

こんばんは。五寳です。すでに IEBlog を読まれた方もいらっしゃるかと思いますが、IE8 RC から RTW にかけて、JScript に変更が入りました。 IEBlog でも JScript Blog

re: What’s new in JScript for IE8

fearphage — Sun, 05 Apr 2009 15:18:44 GMT

@Dan, GauravS: There are two distinct string methods that function differently: substr and substring. Tino referenced substr while Dan referenced the other (substring).

https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/String/substr

https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/String/substring

var sub = string.substr(start[, length]);

Quoting the link above: "If start is negative, substr uses it as a character index from the end of the string. If start is negative and abs(start) is larger than the length of the string, substr uses 0 as the start index. Note: the described handling of negative values of the start argument is not supported by Microsoft JScript."

re: What’s new in JScript for IE8

Dan — Sun, 05 Apr 2009 20:33:53 GMT

fearphage, point to where it says that's a legal syntax (for either method) in the ECMAScript standard, *then* we'll talk.

re: What’s new in JScript for IE8

Dan — Sun, 05 Apr 2009 20:35:45 GMT

I'll also point out that the "parameters" section of the substr method in Mozilla's documentation precludes the use of negative numbers:

"Location at which to begin extracting characters (an integer between 0 and one less than the length of the string)."

VSUG 2009 フォローアップ

Next Web 技術 & More WebLog(鈴木祐巳,Masami Suzuki) — Wed, 17 Jun 2009 05:02:18 GMT

少し前の話になりますが、6月6日のVSUG Dayにて、開発者のInternet Explorer 8対応について話をさせていただきました。そのフォローアップとして少し情報を記述しておきます。 [その１]IE8のイントラネットでのレンダリングモードはIE8互換モード(IE7同等)