php - preg_replace('/[^a-zZ-Z0-9]/', NULL, $action['class']) -

I found a line of code in the project that I am trying to modify / add extension.

  $ Controller = 'Controller' Preg_replace ('/ [^ a-zZ-Z0- 9] /', tap, $ verb ['square']);   
 But I'm not sure this line is the dose which I think is the dose: Capitalizing the first letter, i.e. "order" in "order"  < P> I tried some tests, but this does not make any sense, because it starts to remove the capital letters in words.  
 
  
 This will only remove the first alphanumeric character in the  $ verb ['square'] .  
 If you want to uppercase the letter first, then use it:    $ action ['class'] = ucfirst ($ action ['class']) ;