js判断是否是移动设备登陆网页

var browser = {
            versions: function () {
                var u = navigator.userAgent, app = navigator.appVersion;
                return {//移动终端浏览器版本信息
                    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.*/) || !!u.match(/AppleWebKit/), //是否为移动终端
                    ios: !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/), //ios终端
                    android: u.indexOf('Android') > -1 || u.indexOf('Linux') > -1, //android终端或者uc浏览器
                    iPhone: u.indexOf('iPhone') > -1 || u.indexOf('Mac') > -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 == true || browser.versions.ios == true || browser.versions.android == true) {
            window.location.href = target;
        }