Re: 'in' operator and feature detection technique...

Thomas 'PointedEars' Lahn napisal(a):
> [1] The JScript and JScript.NET References say it was introduced in JScript
> 1.0 already, that would mean IE 3.0 (August 1996). However, I find that
> hard to believe and think that is an error, since a) ECMAScript Ed. 3
> was not published yet and b) it also says that `for (... in ...)' was
> not supported before JScript 5.5 (IE 5.5). I would appreciate it if
> someone could provide reliable test results to back up either claim.

>>From my past posts i have done some testing in 'in' operator and others
(which revealed some features of JavaScript 1.2 (1.3) / JScript
3.0/IE4):
 - for(... in ...) construct is supported since JavaScript 1.2 /
JScript 3.0/IE4, but expressions like [string] in objRef (resulting of
Boolean value) are not supported since IE5.5/JScript 5.5, JavaScript
1.5(?);

others:

- strict equality operators === and !== are supported since JavaScript
1.3 / JScript 3/IE4
- anonymous and named function expressions are supported since
JavaScript 1.3 / JScript 3(?)/IE4 (althought they were not included in
ECMAScript Ed. 1);
- switch/case/default, delete, do/while, labeled continue and labeled
break with array/object initializer ( [ ] / { } ) are supported since
JavaScript 1.2 / JScript 3/IE4 (althought they were not included in
ECMAScript Ed. 1);
- nesting functions inside functions is supported since JavaScript 1.2
/ JScript 3(?)/IE4 (althought they were not included in ECMAScript Ed.
1);

(?) - not 100% sure, maybe someone more knowlegable will correct this;
(since features mentioned above are widely used when creating scripts,
the baseline for those scripts are IE 4 / NN 4(.06)).

B.R.
Luke.
Received on Mon May 1 03:13:47 2006