使用Preg_Replace_Callback函数

Question

Okay, I think the reason why the search bar on this page is broken is because the PHP updated, and preg_replace is deprecated. https://sparklewash.com/

I tried replacing the preg_replace function to preg_replace_callback like so, but I'm still getting some issues.

Original:

function clean($string) {
   $string = str_replace(' ', '-', $string); // Replaces all spaces with hyphens.
   return preg_replace('/[^A-Za-z0-9\-]/', '', $string); // Removes special chars.

}

New Version:

function clean($string) {
   $string = str_replace(' ', '-', $string); // Replaces all spaces with hyphens.
   return preg_replace_callback('/(^|_)([a-z])/', 
   create_function ('$matches', 'return strtoupper($matches[2]);'), $string); // Removes special chars.
}

I apologize if this is easy for you, I was trying to follow an article on here but I'm still relatively new to PHP.

Edit: I belive the preg_replace isn't what broke it due to some of the comments. I've made a new question here to stay on topic: Redirect Loop on $_GET Request

Answer 1

I would not recommend the syntax you are using, the most likely cause of the error, kindly try below syntax.

$result = preg_replace_callback('/(^|_)([a-z])/', function($matches){

   return strtoupper($matches[0]);
   /*
   $matches[0] is the complete match of your regular expression 
   $matches[1] is the match of the 1st round brackets () similarly for $matches[2]...and so on.

   */

}, $string);

//Also $result will contain the resultant string

You have to just pass the $matched to your callback function, you can also declare the callback separately, as an stand alone function.

function make_upper($matches){

   return strtoupper($matches[0]);

}
$result = preg_replace_callback('/(^|_)([a-z])/','make_upper' , $string);

Hope my solution works for you, Thanks. :)