$re = '/(?<=class\s)\s*(.+?)(?=\s*\{)/';
$str = 'class Mango {
class mango
mango {
class _Mango$ {
class ‿Mango{
class mango{
class mango {
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php