JScript version (Standard)

The version history for JScript.


Microsoft added scripting capabilities to version 3.0 of the MSIE browser. The JScript interpreter is perhaps named differently so that detractors would not accuse Microsoft of modifying the JavaScript language.

Version 1.0 of JScript was also available in Internet Information Server as well as the MSIE version 3.0 browser. That first version of JScript is broadly compatible with JavaScript version 1.0 although there are differences between them:

JScript 1.0NoEquivalent to JavaScript 1.0 and released with MSIE 3.0
JScript 1.1NoNever released
JScript 1.2NoEvidence of its existence but status unknown
JScript 2.0NoReleased with IIS 1.0
JScript 3.0YesEquivalent to JavaScript 1.2 and released with MSIE 4.0, IIS 4.0 and WSH 1.0 (some features are in MSIE 3.02)
JScript 4.0YesReleased with Visual Studio 6.0
JScript 5.0YesEquivalent to JavaScript 1.5 and supported on all 32 bit Windows operatings systems with MSIE.
JScript 5.1YesReleased with IIS 5.0 on Windows 2000
JScript 5.5YesReleased with MSIE 5.5

The JScript support in MSIE is excellent. However, if you limit yourself purely to the JavaScript sub-set, there are some limitations in the support. The language has been extended somewhat but not in the same way as Netscape Communications Inc provided enhancements to their interpreter.

If the JScript interpreter is re-installed without upgrading the browser, you may be using a version of JScript that is later than the browser. Scripts should work normally as long they do not exploit features of JScript that have changed. However, the scripts may not be able to access some new features of the later version. For example, JScript 5.5 can be installed over the top of JScript 5.0 in a version 5.0 MSIE browser. You get the later core language features but continue to use the old document model. This can get utterly confusing for script developers.

See also:History, Internet Explorer, JavaScript version


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