判断浏览器环境

const userAgent = navigator.userAgent.toLowerCase();

const browserEnv = {
  isWeixin: /MicroMessenger/i.test(userAgent),
  isGenie:/\(TGenie\/([\d\.]+)\)/i.test(userAgent), //天猫精灵
  isIos: /(iPhone|iPad|iPod|iOS)/i.test(userAgent),
  isWeibo: /WeiBo/i.test(userAgent),
  isQQ: userAgent.indexOf('qq') > -1 || userAgent.indexOf('mqqbrowser') === -1,
  isAlipay: /alipay/gi.test(userAgent),
  isDingDing: userAgent.indexOf('dingtalk') > -1,
  isTrident: userAgent.indexOf('Trident') > -1, //IE内核
  isPresto: userAgent.indexOf('Presto') > -1, //opera内核
  isWebKit: u.indexOf('AppleWebKit') > -1, //苹果、谷歌内核
  isGecko: u.indexOf('Gecko') > -1 && u.indexOf('KHTML') == -1, //火狐内核
  isMobile: !!u.match(/AppleWebKit.*Mobile.*/), //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uc浏览器
  iPhone: u.indexOf('iPhone') > -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
};