判断浏览器类型JS代码

 var browser = {
                    versions: function () {
                        var u = navigator.userAgent,
                            app = navigator.appVersion;
                        return {
                            trident: u.indexOf('Trident') > -1, //IE内核
                            presto: u.indexOf('Presto') > -1, //opera内核
                            webKit: u.indexOf('AppleWebKit') > -1, //苹果、谷歌内核
                            gecko: u.indexOf('Gecko') > -1 && u.indexOf('KHTML') == -1, //火狐内核
                            mobile: !!u.match(/AppleWebKit.*Mobile.*/), //是否为移动终端
                            ios: !!u.match(/(i[^;]+;( U;)? CPU.+Mac OS X/), //ios终端
                            android: u.indexOf('Android') > -1, //android终端或者uc浏览器
                            iPhone: u.indexOf('iPhone') > -1, //是否为iPhone或者QQHD浏览器
                            iPad: u.indexOf('iPad') > -1, //是否iPad
                            webApp: u.indexOf('Safari') == -1 //是否web应该程序，没有头部与底部
                        };
                    }(),
                    language: (navigator.browserLanguage || navigator.language).toLowerCase()
                }
                if (browser.versions.mobile || browser.versions.iPhone || browser.versions.android) {
                    document.write("<script src="js/bootstrap.js">" + "</scr" + "ipt>");
                    document.write("<link  href='css/bootstrap.css.css' rel='stylesheet' type='text/css' />");
                    window.location.href = "/indexPhone/index.html";
                } else {
                    document.write("<script src="/mod/index/index.js">" + "</scr" + "ipt>");
                }