JS distinguishes whether the accessed browser is android or ios system_javascript skills

In the project, you need to scan the QR code to automatically identify whether it is an android or ios system, and perform different downloads for different systems.

<script type="text/javascript">
/*
* 智能机浏览器版本信息:
*
*/
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;)&#63; 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.ios || browser.versions.iPhone || browser.versions.iPad) {
window.location="https://itunes.apple.com/xxx";
}
else if (browser.versions.android) {
window.location="http://xxx/xxx.apk";
}

// document.writeln("语言版本: " + browser.language);
// document.writeln(" 是否为移动终端: " + browser.versions.mobile);
// document.writeln(" ios终端: " + browser.versions.ios);
// document.writeln(" android终端: " + browser.versions.android);
// document.writeln(" 是否为iPhone: " + browser.versions.iPhone);
// document.writeln(" 是否iPad: " + browser.versions.iPad);
// document.writeln(navigator.userAgent);

</script>