How do you find out what version of JavaScript your browser supports?

[wylbur37]

How do you find out what version of JavaScript your browser supports?
Is there a JavaScript function that will tell you?



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[Lasse Reichstein Nielsen]

Re: How do you find out what version of JavaScript your browsersupports ?

wylbur37 <wylbur37nospam @yahoo.com> writes:
[color=blue]
> How do you find out what version of JavaScript your browser supports?[/color]

You don't.

Technically, only Netscape's browsers supports a "version of
JavaScript", since they are the ones defining the JavaScript
versions. The versions are summarized here:
<URL:http://devedge.netscap e.com/library/manuals/2000/javascript/1.5/reference/preface.html#10 03515>

Microsoft browsers have different versions of JScript, which is mostly
compatible with Netscape's JavaScript. They use their own version
numbers.
<URL:http://msdn.microsoft. com/library/en-us/script56/html/js56jsoriversio ninformation.as p>

Other browsers implement their version of ECMAScript + DOM and call it
Javascript, e.g., Opera. They have no version numbers for the Javascript,
it just evolves with the browser.


The core language is pretty fixed by now, as everybody are
implementing ECMAScript v3. The differences are in the interface to
the browser and document, i.e., the DOM.
[color=blue]
> Is there a JavaScript function that will tell you?[/color]

No.

/L
--
Lasse Reichstein Nielsen - lrn@hotpop.com
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleD OM.html>
'Faith without judgement merely degrades the spirit divine.'

[Philip Herlihy]

Re: How do you find out what version of JavaScript your browser supports?

It's worth looking at the version info in the property sheet for
C:\WINDOWS\SYST EM32/jscript.dll

--
############### #######
## PH, London ##
############### #######


Lasse Reichstein Nielsen wrote:[color=blue]
> wylbur37 <wylbur37nospam @yahoo.com> writes:
>[color=green]
>> How do you find out what version of JavaScript your browser supports?[/color]
>
> You don't.
>
> Technically, only Netscape's browsers supports a "version of
> JavaScript", since they are the ones defining the JavaScript
> versions. The versions are summarized here:
>[/color]
<URL:http://devedge.netscape.com/library/...pt/1.5/referen
ce/preface.html#10 03515>[color=blue]
>
> Microsoft browsers have different versions of JScript, which is mostly
> compatible with Netscape's JavaScript. They use their own version
> numbers.
>[/color]
<URL:http://msdn.microsoft.com/library/en...6jsoriversioni
nformation.asp>[color=blue]
>
> Other browsers implement their version of ECMAScript + DOM and call it
> Javascript, e.g., Opera. They have no version numbers for the
> Javascript, it just evolves with the browser.
>
>
> The core language is pretty fixed by now, as everybody are
> implementing ECMAScript v3. The differences are in the interface to
> the browser and document, i.e., the DOM.
>[color=green]
>> Is there a JavaScript function that will tell you?[/color]
>
> No.
>
> /L[/color]

[Fabian]

Re: How do you find out what version of JavaScript your browser supports?

wylbur37 hu kiteb:
[color=blue]
> How do you find out what version of JavaScript your browser supports?
> Is there a JavaScript function that will tell you?[/color]

The best approach is to test within your script for the presence of the
fucntion you want to use, rather than testing for a version number. In
other words, test for what it can do, rather than for what it says it
can do.


--
--
Fabian
Visit my website often and for long periods!

http://www.lajzar.co.uk

[Holden Caulfield]

Re: How do you find out what version of JavaScript your browser supports?

I agree that doing object detection is usually better than using
version detection.

However, in answer to the original question, you could declare a
variable and then test for increasing versions of javascript such as
this:

<script language="javas cript1.1">
<!--
var jsver = 1.1
// -->
</script>
<script language="javas cript1.2">
<!--
jsver = 1.2
// -->
</script>
[and on and on until Nth version of javascript...]

Whatever "jsver" is at the end is your highest version CLAIMED to be
understood.

Holden

[Thomas 'PointedEars' Lahn]

Re: How do you find out what version of JavaScript your browser supports?

Holden Caulfield wrote:
[color=blue]
> I agree that doing object detection is usually better than using
> version detection.[/color]

You bet! http://pointedears.de.vu/scripts/test/whatami
[color=blue]
> However, in answer to the original question, you could declare a
> variable and then test for increasing versions of javascript such as
> this:
>
> <script language="javas cript1.1">
> <!--
> var jsver = 1.1
> // -->
> </script>
> <script language="javas cript1.2">
> <!--
> jsver = 1.2
> // -->
> </script>
> [and on and on until Nth version of javascript...]
>
> Whatever "jsver" is at the end is your highest version CLAIMED to be
> understood.[/color]

I have misguidedly used that years ago. And now -- what should it be
good for if not reliable? It is exactly the wrong way and thus returns
the wrong results. For example, IE 6.0 SP-1 on Win2k claims to support
JavaScript 1.5 but it does not support (not even with updated JScript
engine) core features specified there and in ECMAScript 3. Besides, the
above is invalid HTML 4 as the type attribute is missing, and it will
not validate as HTML 4.01/XHTML 1.0 Strict as the "language" attribute
is deprecated. OTOH, it is unlikely that you get a result even near to
truth if you use both the "language" and the "type" attribute.


PointedEars