I'm trying to parse several coordinates, but PHP preg_match is missing a capture group. It works in every regex simulator I've tested, but not in my code. Group 4 always comes up empty;
$coordinates = 'N40.765775° E8.303369°';
// -40.765775° -8.303369°
// 40.765775° 8.303369°
// -40.765775° 8.303369°
// N40.765775° E8.303369°
// S40.765775° E8.303369°
// N40.765775° W8.303369°
// S40.765775° W8.303369°
$regex = '/([-NnSs]?)\D*([0-9]?[0-9])\.(\d{1,10}+)\D\h*([-EeWw]?)\D*([0-1]?[0-9]?[0-9])\.(\d{1,10}+)/';
if (preg_match($regex, $coordinates, $matches)) {
print_r($matches);
} else {
echo "no matches";
}
Since you are parsing strings that have multibyte characters (°), you should add the unicode modifier, i.e. u at the end of the regex.
/ /u
Just as an illustration: without that modifier, if you would add a . after \D, here:
\D.\h*([-EeWw]?)
... then you would capture the "E" in the fourth capture group. So \D. actually matches the multibyte character °.