php preg_replace_all我需要定义$ matches吗？

Question

I typically call preg_match_all using $pattern, $subject, $matches, like

preg_match_all("/\S/","words",$matches);

However, my IDE (Netbeans) is yelling at me because $matches (which is passed by reference and will be assigned the result of preg_match_all) is undefined so it doesn't want me to pass it as a parameter. Its happy with something like:

$matches=[];
preg_match_all("/\S/","words",$matches);

However, this seems superfluous, and the examples on php.net do not define the variable ahead of time. What is the "proper" way to do this? Can I just ignore Netbeans?

Answer 1

Ignore NetBeans. As you say, the PHP manual doesn't define the variable, and I've tested it with all error reporting on and no notice error is given.

Also, the IDE I use, PHPStorm, doesn't show an undefined error for the $matches variable.