js区分安卓手机和苹果手机

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("苹果机！")
}