How to Calculate distance between two points in php by passing latitude and longitude

In this quick tutorial I am going to share a quick php function to Calculate distance between two points in php using latitude and longitude,This below function calculates the distance between two points.
Passed to function:
lat1, lon1 = Latitude and Longitude of point 1 (in decimal degrees)
lat2, lon2 = Latitude and Longitude of point 2 (in decimal degrees)

Here is the function.

function calDistance($lat1, $lon1, $lat2, $lon2) {
  	$theta = $lon1 - $lon2;
   	$miles = (sin(deg2rad($lat1)) * sin(deg2rad($lat2))) + (cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta)));
   	$miles = acos($miles);
   	$miles = rad2deg($miles);
  	$result['miles'] = $miles * 60 * 1.1515;
   	$result['feet'] = $result['miles'] * 5280;
   	$result['yards'] = $result['feet'] / 3;
   	$result['kilometers'] = $result['miles'] * 1.609344;
  	$result['meters'] = $result['kilometers'] * 1000;
  	return $result; 
}

Example.

$distance = calDistance($lat1='28.7041', $lon1='77.1025', $lat2='26.5041', $lon1='75.0025' );
var_dump($distance);
/*
OUTPUT:
array(5) { ["miles"]=> float(199.07401385446) ["feet"]=> float(1051110.7931515) ["yards"]=> float(350370.26438384) ["kilometers"]=> float(320.37856975259) ["meters"]=> float(320378.56975259) }
*/