A good way to detect Internet Explorer and it's version with JavaScript #internetexplorer #javascript

ie.js

/**
 * Created by Semen Kamenetskiy <skamenetskiy@live.com>
 */

(function (win, doc, div, i, cc) {

    'use strict';

    cc = cc
        .replace('%3E', '>')
        .replace('%3C', '<')
        .replace('%', i);

    /**
     * Creates new HTMLElement
     * @param tagName
     * @param [html]
     * @param [element]
     * @returns {HTMLElement}
     * @private
     */
    function _element(tagName, html, element) {
        element = doc.createElement(tagName);
        element.innerHTML = html;
        return element
    }

    /**
     * Checks if an element has i tag
     * @param element
     * @returns {boolean}
     * @private
     */
    function _hasTag(element) {
        return element.getElementsByTagName(i).length > 0
    }

    /**
     * Checks that the client is using Internet Explorer
     * @returns {boolean}
     * @private
     */
    function _checkIe() {
        return _hasTag(_element(div, cc.replace('#', '')))
    }

    /**
     * Checks Internet Explorer version
     * @param [version]
     * @returns {number}
     * @private
     */
    function _checkVersion(version) {
        version = 9;
        while (version > 5) {
            if (_hasTag(_element(div, cc.replace('#', ' ' + version)))) {
                break
            }
            version--
        }
        return version
    }

    /**
     * This is Internet Explorer less than or equal 9
     * @type {boolean}
     * @expose
     */
    win.IE = _checkIe();

    /**
     * Internet Explorer version (if less than 9)
     * @type {number}
     * @expose
     */
    win.IE_VERSION = _checkVersion();

})(window, document, 'div', 'i', '%3C!--[if IE#]><%></%><![endif]--%3E');

ie.min.js

(function(d,k,e,f,b){function g(a,b,c){c=k.createElement(a);c.innerHTML=b;return c}function h(a){return 0<a.getElementsByTagName(f).length}b=b.replace("%3E",">").replace("%3C","<").replace("%",f);d.IE=h(g(e,b.replace("#","")));d.IE_VERSION=function(a){for(a=9;5<a&&!h(g(e,b.replace("#"," "+a)));)a--;return a}()})(window,document,"div","i","%3C!--[if IE#]><%></%><![endif]--%3E");