根据两点经纬度求两点的距离(Javascript)

这里latlng1的类型是google.maps.LatLng;

function get_distance(latlng1, latlng2)

{

var radLat1 = latlng1.lat() * Math.PI / 180;

var radLat2 = latlng2.lat() * Math.PI / 180;

var a = radLat1 - radLat2;

var b = (latlng1.lng() * Math.PI / 180) - (latlng2.lng() * Math.PI / 180);

var s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a/2),2) +

Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b/2),2)));

s = s * 6378.137;

return s;

}