$mylat = $_SESSION['lat'];
$mylng = $_SESSION['lng'];
$statement = $pdo->prepare("SELECT * FROM users");
$statement->execute();
$users = $statement->fetchAll();
foreach($users as $row){
$dist = 0.0;
$x1 = $mylng;
$x2 = $row['lng'];
$y1 = $mylat;
$y2 = $row['lat'];
$dist = acos(sin($x1=deg2rad($x1))*sin($x2=deg2rad($x2))+cos($x1)*cos($x2)*cos(deg2rad($y2) - deg2rad($y1)))*(6378.137);
$distn = FLOOR ( ROUND($dist,1) * 2 ) / 2 ;
}
sort($distn);
foreach ($users as $row) {
$dist = 0.0;
$x1 = $mylng;
$x2 = $row['lng'];
$y1 = $mylat;
$y2 = $row['lat'];
$dist = acos(sin($x1=deg2rad($x1))*sin($x2=deg2rad($x2))+cos($x1)*cos($x2)*cos(deg2rad($y2) - deg2rad($y1)))*(6378.137);
$distn = FLOOR ( ROUND($dist,1) * 2 ) / 2 ;
echo $row['username'];
echo $distn;
}
因此,在第一个foreach中,我计算了每个用户到我的距离.
比我想对与我的距离后的用户进行排序并显示它们
那里有我的名字,也有我的距离.
user1 0.5km distance
user2 1km distance
但是我不会工作.
谢谢你的帮助 :)
解决方法:
function getdistance ($lat, $lon)
{
global $mylng, $mylat;
$x1 = deg2rad($mylng);
$x2 = deg2rad($lon);
$y1 = deg2rad($mylat);
$y2 = deg2rad($lat);
$dist = acos(sin($x1)*sin($x2)+cos($x1)*cos($x2)*cos($y2 - $y1))*(6378.137);
return $dist;
}
function comparedistance ($user1, $user2)
{
return getdistance ($user1['lat'], $user1['lng']) - getdistance ($user2['lat'], $user2['lng']);
}
然后,您可以通过uasort传递数组:
uasort ($users, 'comparedistance');
有关更多信息,请参见http://php.net/manual/en/function.uasort.php.
编辑:
您的程序可以被重写:
function getdistance ($lat, $lon)
{
global $mylng, $mylat;
$x1 = deg2rad($mylng);
$x2 = deg2rad($lon);
$y1 = deg2rad($mylat);
$y2 = deg2rad($lat);
$dist = acos(sin($x1)*sin($x2)+cos($x1)*cos($x2)*cos($y2 - $y1))*(6378.137);
return $dist;
}
function comparedistance ($user1, $user2)
{
return getdistance ($user1['lat'], $user1['lng']) - getdistance ($user2['lat'], $user2['lng']);
}
$mylat = $_SESSION['lat'];
$mylng = $_SESSION['lng'];
$statement = $pdo->prepare("SELECT * FROM users");
$statement->execute();
$users = $statement->fetchAll();
uasort ($users, 'comparedistance');
foreach ($users as $row) {
$dist = getdistance ($row['lat'], $row['lng']);
$distn = floor(round($dist,1) * 2) / 2 ;
echo $row['username']. ": " . $distn . "km distance";
}