CODE EXAMPLE FOR JAVASCRIPT

latitude and longitude distance calculate in node js

function distance(lat1, lon1, lat2, lon2) {
	var p = 0.017453292519943295;    // Math.PI / 180
	var c = Math.cos;
	var a = 0.5 - c((lat2 - lat1) * p)/2 + 
			c(lat1 * p) * c(lat2 * p) * 
			(1 - c((lon2 - lon1) * p))/2;
  
	return 12742 * Math.asin(Math.sqrt(a)); // 2 * R; R = 6371 km
}
console.log(distance(51.5103, 7.49347, 51.5200, 7.49347))

//$uj@y