Determining what classes are defined in a PHP class file

Question

Given that each PHP file in our project contains a single class definition, how can I determine what class or classes are defined within the file?

I know I could jus

Answer 1

Or you could easily use AnnotationsParser from Nette\Reflection (installable using composer):

use Nette\Reflection\AnnotationsParser;
$classes = AnnotationsParser::parsePhp(file_get_contents($fileName));
var_dump($classes);

Output will be then something like this:

array(1) {
  ["Your\Class\Name"] =>
  array(...) {
      // property => comment
  },
  ["Your\Class\Second"] =>
  array(...) {
      // property => comment
  },
}

The parsePhp() method basically does something similar as examples in other answers, but you don't have to declare nor test the parsing yourselves.