JavaScript 计算经纬度距离

const EARTH_RADIUS = 6378.137; //地球半径  
 
const rad = (d) => {
  return d * Math.PI / 180.0;
}
/** 
 * 谷歌地图计算两个坐标点的距离 
 * @param lng1  经度1 
 * @param lat1  纬度1 
 * @param lng2  经度2 
 * @param lat2  纬度2 
 * @return 距离（千米） 
 */
const getDistance = (lng1, lat1, lng2, lat2) => {
  const radLat1 = rad(lat1);
  const radLat2 = rad(lat2);
  const a = radLat1 - radLat2;
  const b = rad(lng1) - rad(lng2);
  let 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 * EARTH_RADIUS;
  s = Math.round(s * 10000) / 10000;
  return s;
}

const a = getDistance(30.27895275, 119.9921260576, 30.2832692396, 120.0249984587)
console.log(a)