スマホで画面の縦と横を判定する

使わなくなったので供養

const ua = navigator.userAgent.toLowerCase()
        // iPhone
        const isiPhone = (ua.indexOf('iphone') > -1)
        // iPad
        const isiPad = (ua.indexOf('ipad') > -1)
        // Android
        const isAndroid = (ua.indexOf('android') > -1) && (ua.indexOf('mobile') > -1)
        // Android Tablet
        const isAndroidTablet = (ua.indexOf('android') > -1) && (ua.indexOf('mobile') == -1)

        const directionCheck = () => {
          const direction = Math.abs(window.orientation)
          if(direction == 90) {
            alert('横向き')
          } else {
            alert('縦向き')
          }
        }

        // iOS
        if(isiPhone || isiPad) {
          window.onorientationchange = directionCheck
        }
        // Android
        if(isAndroid || isAndroidTablet) {
          window.onresize = directionCheck
        }
        directionCheck()