dean.edwards.name/weblog/2007/03/sniff/

Sniff!

My current frog exaggerator of choice:

var isMSIE = /*@cc_on!@*/false;

Comments (68)

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It seems to be the fastest and shortest way to know that, thank You!

ooops, maybe this one is even more horrible :D

var isMSIE = /*@cc_on!@*/!1;

reduced by 3 chars :rotfl:

[...] Dean Edwards nous propose la méthode la plus courte (en terme de code )que j’ai eu l’occasion de voir. [...]

@Andrea – your solution is actually one extra byte after going through packer (assuming you use false somewhere else in your script).

  • Comment by: -dean
  • Posted:
var isMSIE = /*@cc_on!@*/0;

4 chars ;-)

  • Comment by: Boris
  • Posted:

Well if we’re having a competition:

var isMSIE/*@cc_on=1@*/;
  • Comment by: -dean
  • Posted:

m/*@cc_on=1@*/

Hmm, maybe we better just admin Dean already won.

  • Comment by: Doekman
  • Posted:
var isMSIE//@cc_on=1

is a touch shorter but rather more suspect since it takes advantage of the stupid optional-semicolon parsing rules…

  • Comment by: sil
  • Posted:

@sil – curse you! I didn’t know that IE supported single line conditional comments. Now I have to go refactor packer…

  • Comment by: -dean
  • Posted:

Dean: can’t guarantee that it works in all IEs, just in the one on my desktop…

  • Comment by: sil
  • Posted:

come on guys, I didn’t change original result, my solution mantains exactly Dean proposal, a Boolean constructor for isMSIE variable so it’s a JSON “true” or “false” string, not “0″ or “1″ one :D (ok, it’s not so important and I’m joking)

@sil … I need to update my Cruncher.class.php too (damn, I didn’t know single line comment did it!), however the stupid optional-semicolon is the most important char for an inline (crunched) script ;)

ie5/mac ignores conditional comments, yes?

  • Comment by: Eric Gerds
  • Posted:

This is the first time I see this in a single line comment. Cool!

  • Comment by: Kevinin
  • Posted:

Eric, nope.

Dean, it surprises me this works inside an eval() statement!

Hold on, goshdarnit, I haven’t *tested* that across IE versions. Someone needs to test the single-line-comment version before everyone rewrites all the code in the world to use it ;)

  • Comment by: sil
  • Posted:

sil, it seems to work correctly with my IE 4, 5, 5.5, 6 (stand alone versions) and 7 too.

It’s cool enought, now I could do strange things like this one:

if(1)//@cc_on;/*

alert("Hello !IE browser");

//*/

the way to use IE conditional comments not for IE but for every other browsers, lol :D

.. ehr, probably last comment should be a cc too (for cruncher or parser rules)

if(1)//@cc_on;/*

alert("Hello !IE browser");

//@cc_on*/

alert("Hello IE too");

bye and thank you :)

Got one of those for isStrict?

  • Comment by: Doug Hendricks
  • Posted:

… ehr (again) … I’m not spamming, I’m just sleeping, sorry :D

//@cc_on/*

alert("Hello !IE browser");

//@cc_on*/

alert("Hello IE too");

You could always cut off the ‘is’ from the beginning.

  • Comment by: Dannii
  • Posted:

damn it! i lost this competiotion, but if we have to sniff why don’t do it heavily???

var IEVersion=/*@cc_on function(){ switch(@_jscript_version){ case 1.0:return 3; case 3.0:return 4; case 5.0:return 5; case 5.1:return 5; case 5.5:return 5.5; case 5.6:return 6; case 5.7:return 7; }}()||@*/0;

minor version are ignored..and i don’t know about mac version ..

@kentaromiura – or you could do this:

var IEVersion = 0 /*@cc_on+ScriptEngineMajorVersion()@*/;
  • Comment by: -dean
  • Posted:

so for the record, this is best, yeah?

m//@cc_on=1

@Doug -

var isStrict = document.compatMode == "CSS1Compat";
  • Comment by: -dean
  • Posted:

@Dustin – Yep. You win a cuddly pink teddy bear. You can call him “Pinkie”.

  • Comment by: -dean
  • Posted:

@Dean- [grin] was hoping for 6 chars or less.

  • Comment by: Doug Hendricks
  • Posted:

[...] Dean also had some fun sniffing browsers and came up with the short test. [...]

I expect my pink teddy bear in the mail. thank you.

Is it alright if I have no idea what you people are talking about?

My Version:

var isMSIE = true; isMSIE = /*@cc_on!@*/false;

  • Comment by: Andi
  • Posted:

My version:

var isMSIE = /msie/.test(navigator.userAgent.toLowerCase())

You guys just make it such hard work…

:)

[...] Dean Edwards gives us a nice lean way, using Javascript conditional compilation, to detect IE: var isMSIE = /*@cc_on!@*/false; [...]

This is just great! I will use it from now on. :)

Alistair Potts: Are you joking? Opera used to introduce itself as MSIE.

And Andi’s comment seems after the whole discussion as spam too.

  • Comment by: Cezary Okupski
  • Posted:

my preference going forward has been this:

var jscript/*@cc_on=@_jscript_version@*/;

then you can code upon it as

if (self.jscript) // IE
else if (self.jscript >= 5.5) // IE 5.5 +
else if (self.jscript == 5.7) // IE 7.0 Vista
  • Comment by: Lucky
  • Posted:

@Lucky – brilliant!

  • Comment by: -dean
  • Posted:

[...] Dean Edwards придумав один з найлаконічніших способів ідентифікації Internet Explorer’а в JavaScript: Sniff! [...]

[...] Самый короткий способ определения Internet Explorer на JavaScript предложил в своем блоге Dean Edwards: [...]

[...] Sniff! – JavaScript IE detector m//@cc_on=1 (tags: JavaScript Conditional Detectors) [...]

@Dean – Thanks, just want to give back for all the great code/innovations you’ve brought forth.

  • Comment by: Lucky
  • Posted:

I prefer var isIE = !!document.protocol; because I can easily memorize this formula… ;)

  • Comment by: Wiktor
  • Posted:

I found best code with 14(13) symbols.

IE=0//@cc_on+1

alert(IE)

More shorts (by sil or Dustin Diaz (11)) require self.IE in condition.

  • Comment by: 12345c
  • Posted:

@Dean: Thanks! I didn’t realize you could use conditional compilation to just hide a “!” from other browsers. I had been using this: /*@cc_on @if(@_jscript) var isIE=true; @else */ var isIE=false; /*@end @*/

To respond to Eric Gerds’ question: IE5/Mac does not support conditional comments, but these are conditional compilations, not conditional comments. Conditional compilation is a feature of JScript which IE5/Mac uses, so it does support this.

  • Comment by: Kravvitz
  • Posted:

@Dean – Thanks! I just wanted to let you know that I am thankful for all the great innovations and idea you’ve displayed in your blog.

[...] Simple IE detection in JavaScript (var isMSIE = /*@cc_on!@*/false; and more in the comments) [...]

Nice and elegant method, and very short too ;)

  • Comment by: henri
  • Posted:

[...] Depois de familiarizarmos com a sintaxe, podemos escrever códigos como o que Dean Edwards postou aqui: [...]

Looking at how simple this is makes me feel warm inside.

  • Comment by: Lachlan
  • Posted:

I’ve just realized that “snif” is a worldwide expression :D

[Alex from France]

  • Comment by: Alex
  • Posted:

One more code snippet found: arguments and DOM collections can be treated like native Array.
Examples:

function bind_params(fn){
    var args=[].slice.call(arguments,1);
    return function(){ fn.call(window,args); }
}
[].slice.call(document.getElementsByTagName('*'),20);

It is easier to write this way and should work faster.

  • Comment by: DPP
  • Posted:

[...]     var jscript = NaN/*@cc_on||@_jscript_version@*/; // http://dean.edwards.name/weblog/2007/03/sniff/#comment85164 [...]

hi very thanks

  • Comment by: kompak
  • Posted:

[...] simple way to check if the user is having the Internet Explorer web browser, suggested by Dean Edwards (lots of geeky comments here), is to do it like [...]

For the poor people reading this in 2008: The comment in comment #35

else if (self.jscript == 5.7) // IE 7.0 Vista

should actually read

else if (self.jscript == 5.7) // IE 6.0 XP SP3

Somebody told me “I told you so” in the neighbourhood of 2006 :-)

(of course there’s no problem if you really just use this to work around JScript version bugs)

  • Comment by: eric
  • Posted:

[...] une des manières les plus courtes pour savoir si le navigateur est Internet Explorer avec var isMSIE = /@cc_on!@/false; ou plus court encore var isMSIE = [...]

[...] ); O puedes usar otro método más reciente de Dean Edrwards [...]

[...] http://dean.edwards.name/weblog/2007/03/sniff/ [...]

@lucky, eric (comments #35/#54) and others: it is not a good idea to get the browser version by checking the version of its scripting engine: they are independent. See point 4 of this comment.

  • Comment by: Marcel Korpel
  • Posted:

Oh, by the way, that post gives a shorter form of your frog exaggerator:

if(!+"\v1") // true only in IE

But, as noted in another comment, you’ll never be sure if another browser will treat a vertical tab the same way as IE. The same is true for conditional compilation, of course.

  • Comment by: Marcel Korpel
  • Posted:

[...] This is the most compact and insane hack I have ever come across for IE-detection (courtesy: http://dean.edwards.name/weblog/2007/03/sniff/ [...]

var isMSIE = ‘\a’===’a';

  • Comment by: Paul B.
  • Posted:

[...] This is the most compact and insane hack I have ever come across for IE-detection (courtesy: http://dean.edwards.name/weblog/2007/03/sniff/ [...]

This is such a great resource that you are providing and you give it away for free. I love seeing blog that understand the value of providing a quality resource for free.

  • Comment by: Sarkari naukri
  • Posted:

For anyone that uses Google Closure Compiler, this may be of use to you:

var isMSIE = eval("/*@cc_on!@*/!1");
  • Comment by: Chris West
  • Posted:

i don’t understand comment 35 those else ifs will not get executed if the first if is true

  • Comment by: john
  • Posted:

[...] ref [...]

  • Pingback by: Anonymous
  • Posted:

I am using code in MVC 4.0 but below code makes comment in rest of the MVC code. Please guide me. I want to detect IE browser and version of IE.

var isIE = new Function(“return/*@cc_on!@*/!1″)( ); // [Boolean]

  • Comment by: Monal
  • Posted:

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  • Comment by: sparxx rx
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