detect browser

detech_browser.js

// method one https://stackoverflow.com/revisions/9851769/1
var isOpera = !!(window.opera && window.opera.version);  // Opera 8.0+
var isFirefox = testCSS('MozBoxSizing');                 // FF 0.8+
var isSafari = Object.prototype.toString.call(window.HTMLElement).indexOf('Constructor') > 0;
    // At least Safari 3+: "[object HTMLElementConstructor]"
var isChrome = !isSafari && testCSS('WebkitTransform');  // Chrome 1+
var isIE = /*@cc_on!@*/false || testCSS('msTransform');  // At least IE6

function testCSS(prop) {
    return prop in document.documentElement.style;
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

// method two https://stackoverflow.com/questions/9847580/how-to-detect-safari-chrome-ie-firefox-and-opera-browser
// Opera 8.0+
var isOpera = (!!window.opr && !!opr.addons) || !!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0;

// Firefox 1.0+
var isFirefox = typeof InstallTrigger !== 'undefined';

// Safari 3.0+ "[object HTMLElementConstructor]" 
var isSafari = /constructor/i.test(window.HTMLElement) || (function (p) { return p.toString() === "[object SafariRemoteNotification]"; })(!window['safari'] || (typeof safari !== 'undefined' && safari.pushNotification));

// Internet Explorer 6-11
var isIE = /*@cc_on!@*/false || !!document.documentMode;

// Edge 20+
var isEdge = !isIE && !!window.StyleMedia;

// Chrome 1+
var isChrome = !!window.chrome && !!window.chrome.webstore;

// Blink engine detection
var isBlink = (isChrome || isOpera) && !!window.CSS;