Question: how to calculate distance between two places in php?
Answer: php function distance($lat1, $lon1, $lat2, $lon2) { $pi80 = M_PI / 180; $lat1 *= $pi80; $lon1 *= $pi80; $lat2 *= $pi80; $lon2 *= $pi80; $r = 6372.797; // mean radius of Earth in km $dlat = $lat2 - $lat1; $dlon = $lon2 - $lon1; $a = sin($dlat / 2) * sin($dlat / 2) + cos($lat1) * cos($lat2) * sin($dlon / 2) * sin($dlon / ...