js判断浏览器类型，设备类型

var os = function () {
   var ua = navigator.userAgent.toLowerCase(),
      isAndroid = /(?:android)/.test(ua),
      isWeChat = /(?:micromessenger)/.test(ua),
      isQQ = /(?:qq)/.test(ua),
      isWeiBo = /(?:weibo)/.test(ua),
      isTablet = /(?:ipad|playbook)/.test(ua) || (isAndroid && !/(?:mobile)/.test(ua)),
      isPhone = /(?:iphone)/.test(ua) && !isTablet,
      isPc = !isPhone && !isAndroid && !isTablet;
   return {
      isTablet: isTablet,// 平板
      isPhone: isPhone, // 苹果
      isAndroid: isAndroid, //安卓
      isWeChat: isWeChat, //微信
      isQQ: isQQ, // QQ
      isWeiBo: isWeiBo, // 微博
      isPc: isPc // PC端
   };
}();

//使用
if (os.isPc) {
   console.log(‘isPc :‘);
} else if (os.isAndroid) {
   console.log(‘isAndroid‘);
}
else if (os.isPhone) {
   console.log(‘isPhone‘);
}