Understand how to extract substrings in PHP

Question

I have a URL in the format

$string ='https://test.com/uploads/2023/02/06/1/18413/themes/2725/images/dvd_jacket_pdf/dvd_jacket_20630 .pdf';

I need to extract 2725, which is a topic ID, in the application. Can I do this in PHP using regular expressions? I think the logic should be to extract the characters between the subject string and //.

preg_match('#themes/(.d )#', $string, $check);

I also want to add slashes to this regex.

Answer 1

You don't need to use a slash, and you have an extra dot in the pattern. Just use this:

$string = 'https://test.com/uploads/2023/02/06/1/18413/themes/2725/images/dvd_jacket_pdf/dvd_jacket_20630.pdf';
if(preg_match('#themes/(\d+)#', $string, $check))
    echo $check[1];