How do I run this regex in PHP?

Question

I have this complex PHP I copied online:

[a-z0-9!#$%&\'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&\'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-         


        

Answer 1

You are using a forward slash / as the delimiter. Since you're using the / character inside the expression, you need to escape it using a backslash character - so, instead of /, you'll need to write \/.

The corrected version would be:

$regex = '/[a-z0-9!#$%&\'*+\/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&\'*+\/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?/';

Demo