JScript version availability for WSH installations

Question

I'm not sure if JScript for WSH is available in every windows installation.

Which version of JScript is available for WSH, and in which windows version?

Please provide the link to an authoritative source.

Answer 1

All JScript and Windows Script Host versions are documented in MSDN:

• JScript Version Information
• Windows Script Host Version Information

Answer 2

One not obvious nuance: JScript works like version 5.7 in Windows Script Host 5.8.

From MSDN: Note Starting with JScript 5.8, by default, the JScript scripting engine supports the language feature set as it existed in version 5.7. This is to maintain compatibility with the earlier versions of the engine. To use the complete language feature set of version 5.8, the Windows Script interface host has to invoke IActiveScriptProperty::SetProperty. (MSDN, JScript Version Information)

Worse yet, JScript claims version 5.8 (not 5.7) in such default case (see output of [ScriptEngineMajorVersion(), ScriptEngineMinorVersion()]).

JScript 5.8 introduced the following features: JSON object, JSON.parse method, JSON.stringify method, toJSON method, defineProperty method, getOwnPropertyDescriptor method.

Unfortunately, no simple way to use these features in cscript (or wscript) host of version 5.8. Update: one trick was found by @rojo in 2015. The trick is based on htmlfile COM object and it allows to use at least some of the mentioned features.

See also question 19445189 cscript jscript JSON.