$(function () {    var u = navigator.userAgent, app = navigator.appVersion;    var isAndroid = u.indexOf('Android') > -1 || u.indexOf('Linux') > -1; //g    var isIOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/); //ios终端    if (isAndroid) {        alert("安卓机！")    }    if (isIOS) {        alert("苹果果机！")    }});