js calculates the distance between two places based on longitude and latitude

Calculate the distance between two places based on their latitude and longitude.

function space(lat1, lng1, lat2, lng2) {
		      console.log(lat1, lng1, lat2, lng2)
		      var radLat1 = lat1 * Math.PI / 180.0;
		      var radLat2 = lat2 * Math.PI / 180.0;
		      var a = radLat1 - radLat2;
		      var b = lng1 * Math.PI / 180.0 - lng2 * Math.PI / 180.0;
		      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;
		      s = Math.round(s * 10000) / 10000;
		      return s  // 单位千米
		    }