JScript
JScript is
Microsoft's
Active Scripting implementation of
ECMAScript. JScript was first supported in
Internet Explorer browser 3.0 released in August
1996. When web developers talk about using
JavaScript in Internet Explorer, they are actually using JScript. As with any other Active Scripting engine, it is available through Internet Explorer,
Windows Script Host, and
Active Server Pages. The typical
file extension of JScript
source code files is
.js.
The most recent version of JScript is
JScript .NET, which is based on the yet-unfinished version 4 of the ECMAScript standard, and can be compiled for the
Microsoft .NET platform. JScript adds several new features to ECMAScript, such as optional static type annotations.
Among internal implementation differences, unlike
JavaScript (the original implementation of which is the
SpiderMonkey engine), JScript appears to use a reference counting
Garbage collection implementation, allowing server-provided client-side scripts to easily cause memory leaks unless properly designed to avoid cyclic references.
| Version | Date | Introduced with | Approx. JavaScript | | 1.0 | Aug 1996 | IE 3.0 | 1.0 |
| 2.0 | Jan 1997 | IIS 3.0 | 1.1 |
| 3.0 | Oct 1997 | IE 4.0 | 1.3 |
| 4.0 | | VS 6.0 |
| 5.0 | Mar 1999 | IE 5.0 | 1.5 |
| 5.1 | IE 5.01 | 1.5 |
| 5.5 | Jul 2000 | IE 5.5 | 1.5 |
| 5.6 | Oct 2001 | IE 6.0 | 1.5 |
| .NET | 2000-7-11 | Microsoft .NET Framework 1.0 | 2.0 |
| 8.0 | ? | ? | 2.0 |
(Source:
MSDN,
WebmasterWorld Forum)
*
Hello World program in JScript*
JavaScript, the first ECMAScript implementation which also helped to evolve the ECMAScript standard
*
ECMAScript, the
ECMA language definition standard which all implementations must at a minimum follow
*
Microsoft JScript resources in the MSDN Library
