带有变量的PHP preg_replace（）给出了警告错误

Question

This command gives me a warning, and I would like to know how to fix it.

$countDaily = preg_replace($demande_portabilite, "", $last_request);

This is the error I'm getting : Warning: preg_replace(): Delimiter must not be alphanumeric or backslash in /var/www/html/PortabiliteForm.php on line 22

Thank you for the help :)

Answer 1

You need to surround your pattern with some delimiters. Usually the delimiter used is /. So for your code:

$countDaily = preg_replace("/" . $demande_portabilite . "/", "", $last_request);