What version of JavaScript does ASP Classic use?

Question

The hacks I've seen for identifying a JavaScript version are all tailored to the browser, not an ASP Classic server running JavaScript.

(And no, I'm not running ASP Classic/JavaScript by choice.)

Lamebrain

Out of curiosity, how is server-side JavaScript involved with ASP Classic? – Expiation

@Expiation — JScript is one of the more common languages used for Classic ASP. I think only VBScript is more common. (The only other language I've heard of being used is PerlScript via a plugin that ActiveState used to make) – Ridley

@Ridley so it used JScript on the server? Huh. I did a tiny bit of ASP work back around 1999 or so but it was all VB. So server-side JScript had some sort of COM integration I guess. Weird. – Expiation

No @Expiation JScript (Microsoft implementation of ECMAScript) is an ActiveX Scripting language and available in Classic ASP by using the <%@ Language = "JScript" %> processing directive. Do not confuse JScript with JavaScript there are differences (as @Dai point's out in their answer below). – Hestia

@Lankymart <%@ language=JavaScript %> also works, at least sometimes. It's what the system I'm using starts its ASP files with. – Lamebrain

@ShayGuy You're right it does but that is just an alias that maps to JScript. The scripting engine used is the same. – Hestia

Thanks for clarifying that you are not running it by choice. The amount of foul things I could say about Classic ASP are so numerous that it would take a book twice as thick as Les Miserables. – Kyle

Answer 1

Disclaimer: I'm an engineer on Microsoft's JavaScript team (specifically, Chakra).

The IActiveScript JavaScript engine used by "Classic ASP" is also used by the Windows Script Host (cscript and wscript) and was also used by IE for a while (IE9 and later, certainly does not).

Anyway, the JScript engine generally coincides with the ECMAScript 3.0 specification with some proprietary extensions (such as ActiveXObject). The specification is available here: http://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262,%203rd%20edition,%20December%201999.pdf - this specification was written in 1999.

This version of JScript has not been updated much since the days of Windows 2000 (i.e. no new features have been added, the only changes have been for the benefit of security).

As such, it does not include features introduced in ECMAScript 5, like strict mode, or Array.isArray.

Ludivinaludlew