【JS】Haversine公式计算经纬度之间的距离

let computedDistance = function getDistanceFromLatLonInKm(lat1, lon1, lat2, lon2) {
       Number.prototype.deg2rad = function (deg) {
           return deg * (Math.PI / 180)
       };
       var R = 6371; // Radius of the earth in km
       var dLat = 0..deg2rad(lat2 - lat1);  // deg2rad below
       var dLon = 0..deg2rad(lon2 - lon1);
       var a =
           Math.sin(dLat / 2) * Math.sin(dLat / 2) +
           Math.cos(0..deg2rad(lat1)) * Math.cos(0..deg2rad(lat2)) *
           Math.sin(dLon / 2) * Math.sin(dLon / 2)
       ;
       var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
       var d = R * c; // Distance in km
       return d;
   }