js获取浏览器版本

获取火狐，谷歌，ie，常见浏览器的方法

function myBrowser(){
	var userAgent = navigator.userAgent,
	rMsie = /(msie\s|trident.*rv:)([\w.]+)/,
	rFirefox = /(firefox)\/([\w.]+)/,
	rOpera = /(opera).+version\/([\w.]+)/,
	rChrome = /(chrome)\/([\w.]+)/,
	rSafari = /version\/([\w.]+).*(safari)/;
	var browser;
	var version;
	var ua = userAgent.toLowerCase();
	function uaMatch(ua){
	  var match = rMsie.exec(ua);
	  if(match != null){
	    return { browser : "IE", version : match[2] || "0" };
	  }
	  var match = rFirefox.exec(ua);
	  if (match != null) {
	    return { browser : match[1] || "", version : match[2] || "0" };
	  }
	  var match = rOpera.exec(ua);
	  if (match != null) {
	    return { browser : match[1] || "", version : match[2] || "0" };
	  }
	  var match = rChrome.exec(ua);
	  if (match != null) {
	    return { browser : match[1] || "", version : match[2] || "0" };
	  }
	  var match = rSafari.exec(ua);
	  if (match != null) {
	    return { browser : match[2] || "", version : match[1] || "0" };
	  }
	  if (match != null) {
	    return { browser : "", version : "0" };
	  }
	}
	var browserMatch = uaMatch(userAgent.toLowerCase());
	if (browserMatch.browser){
	  browser = browserMatch.browser;
	  version = browserMatch.version;
	}
	var x = browser+parseInt(version);
	console.log(x);
	return x
}