function sayswho() {
var ua = navigator.userAgent,
tem,
M = ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || [];
if (/trident/i.test(M[1])) {
tem = /\brv[ :]+(\d+)/g.exec(ua) || [];
return 'IE ' + (tem[1] || '');
}
if (M[1] === 'Chrome') {
tem = ua.match(/\b(OPR|Edge)\/(\d+)/);
if (tem !== null) {
return tem.slice(1).join(' ').replace('OPR', 'Opera');
}
}
M = M[2] ? [M[1], M[2]] : [navigator.appName, navigator.appVersion, '-?'];
if ((tem = ua.match(/version\/(\d+)/i)) !== null) {
M.splice(1, 1, tem[1]);
}
return M.join(' ');
}
some other ways
// Opera 8.0+
var isOpera = (!!window.opr && !!opr.addons) || !!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0;
// Firefox 1.0+
var isFirefox = typeof InstallTrigger !== 'undefined';
// At least Safari 3+: "[object HTMLElementConstructor]"
var isSafari = Object.prototype.toString.call(window.HTMLElement).indexOf('Constructor') > 0;
// 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;
