ArrayList<LatLng> compare to another one LatLng for distance calculation and store the result in ArrayList

Question

Now I have multiple LatLng values stored inside ArrayList<LatLng> locations = new ArrayList<>(); and one LatLng TGlatlng value. I want to loop through Array and get each value of Array and compare to one LatLng TGlatlng to calculate distance. After that store the result in the ArrayList<Double> distance = new ArrayList<>() .

for(LatLng location : locations){
     int Radius = 6371;// radius of earth in Km
     double lat1 = location.latitude;
     double lat2 = TGlatlng.latitude;
     double lon1 = location.longitude;
     double lon2 = TGlatlng.longitude;
     double dLat = Math.toRadians(lat2 - lat1);
     double dLon = Math.toRadians(lon2 - lon1);
     double a = Math.sin(dLat / 2) * Math.sin(dLat / 2)
                + Math.cos(Math.toRadians(lat1))
                * Math.cos(Math.toRadians(lat2)) * Math.sin(dLon / 2)
                * Math.sin(dLon / 2);
     double c = 2 * Math.asin(Math.sqrt(a));
     double valueResult = Radius * c;
     double km = valueResult / 1;
     ArrayList<Double> distance = new ArrayList<>();
     distance.add(km); 
}

This is what I have done so far and I'm stuck, I don't get any value inside ArrayList distance , anyone have idea?

Answer 1

The 'haversine' formula looks to be correctly implemente, not sure why distance is created inside the for loop. can you take it out and try.