是否是某类手机型号

// 用devicePixelRatio和分辨率判断
const isIphonex = () => {
  // X XS, XS Max, XR
  const xSeriesConfig = [
    {
      devicePixelRatio: 3,
      width: 375,
      height: 812
    },
    {
      devicePixelRatio: 3,
      width: 414,
      height: 896
    },
    {
      devicePixelRatio: 2,
      width: 414,
      height: 896
    }
  ];
  // h5
  if (typeof window !== "undefined" && window) {
    const isIOS = /iphone/gi.test(window.navigator.userAgent);
    if (!isIOS) return false;
    const { devicePixelRatio, screen } = window;
    const { width, height } = screen;
    return xSeriesConfig.some(
      item =>
        item.devicePixelRatio === devicePixelRatio &&
        item.width === width &&
        item.height === height
    );
  }
  return false;
};