Fuckin' IE Detection, the "hawt" way!

ie_inspector.js

// @author: Vishal Telangre <the@vishaltelangre.com>
// Published under MIT license.
//
// Requires: jQuery
//
// Usage:
//
// ieInspector.isIe
//  -- returns
//     - true for IE browsers
//     - false for non-IE browsers
// ieInspector.ieVersion
//  -- returns
//    - "6.0", "7.0", "8.0", etc. for IE browsers
//    - undefined for non-IE browsers

window.ieInspector = (function() {
  var browser = $.browser;
  var self = this;
  return {
    isIe: function() {
      return browser.hasOwnProperty("msie");
    }(),
    ieVersion: function(){
      if (browser.hasOwnProperty("msie"))
        return browser.version;
      else
        return undefined;
    }()
  };
}());

ie_version_check_v1.js

// ----------------------------------------------------------
// A short snippet for detecting versions of IE in JavaScript
// without resorting to user-agent sniffing
// ----------------------------------------------------------
// If you're not in IE (or IE version is less than 5) then:
//     ie === undefined
// If you're in IE (>=5) then you can determine which version:
//     ie === 7; // IE7
// Thus, to detect IE:
//     if (ie) {}
// And to detect the version:
//     ie === 6 // IE6
//     ie > 7 // IE8, IE9 ...
//     ie < 9 // Anything less than IE9
// ----------------------------------------------------------
 
// UPDATE: Now using Live NodeList idea from @jdalton
 
var ie = (function(){
 
    var undef,
        v = 3,
        div = document.createElement('div'),
        all = div.getElementsByTagName('i');
    
    while (
        div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->',
        all[0]
    );
    
    return v > 4 ? v : undef;
    
}());

// REFERENCE: https://gist.github.com/padolsey/527683#file-gistfile1-js

ie_version_check_v2.js

var ie = (function(){

    var undef, v = 3, div = document.createElement('div');

    // the while loop is used without an associated block: {}
    // so, only the condition within the () is executed.

    // semicolons arent allowed within the condition,
    //   so a comma is used to stand in for one
    // basically allowing the two separate statements 
    //   to be evaluated sequentially.

    while (
        div.innerHTML = '<!--[if gt IE '+(++v)+']><i></i><![endif]-->',
        div.getElementsByTagName('i')[0]
    );

    // each time it's evaluated, v gets incremented and
    //   tossed into the DOM as a conditional comment
    // the i element is then a child of the div.

    // the return value of the getEBTN call is used as 
    //   the final condition expression
    // if there is an i element (the IE conditional
    //   succeeded), then getEBTN's return is truthy
    // and the loop continues until there is no 
    //   more i elements.

    // In other words:  ** MAGIC**

    return v > 4 ? v : undef;

}());

// REFERENCE: https://gist.github.com/padolsey/527683#comment-7599

ie_version_check_v3.js

// For all how what to detect IE10:


(function() {
  "use strict";
  var tmp = (document["documentMode"] || document.attachEvent) && "ev"
       , msie = tmp 
                  && (tmp = window[tmp + "al"])
                  && tmp("/*@cc_on 1;@*/")
                  && +((/msie (\d+)/i.exec(navigator.userAgent) || [])[1] || 0)
  ;
  return msie || void 0;
})();

// REFERENCE: https://gist.github.com/padolsey/527683/#comment-768383

ie_version_check_v4.js

var ie = (function(){
    // for-loop saves characters over while
    for( var v = 3,
             // b just as good as a div with 2 fewer characters
             el = document.createElement('b'),
             // el.all instead of el.getElementsByTagName('i')
             // empty array as loop breaker (and exception-avoider) for non-IE and IE10+
             all = el.all || [];
         // i tag not well-formed since we know that IE5-IE9 won't mind
         el.innerHTML = '<!--[if gt IE ' + (++v) + ']><i><![endif]-->',
         all[0];
       );
    // instead of undefined, returns the documentMode for IE10+ compatibility
    // non-IE will still get undefined as before
    return v > 4 ? v : document.documentMode;
}() );

// MINIFIED VERSION:

var ie=function(){for(var a=3,b=document.createElement("b"),c=b.all||[];b.innerHTML="<!--[if gt IE "+ ++a+"]><i><![endif]-->",c[0];);return 4<a?a:document.documentMode}();

// REFERENCE: https://gist.github.com/padolsey/527683/#comment-786682