preg替换url中的第二个子串

Question

I need to remove the second occurrence of a substring from an url. So, my urls are something like this:

http://example.com/<category>/<category>-<subcategory>-<id>

e.g.

http://example.com/laptop/laptop-hp-probook-101 must be http://example.com/laptop/hp-probook-101

or

http://example.com/computer-parts/computer-parts-cool-motherboard-123 must be http://example.com/computer-parts/cool-motherboard-123

I tried this:

$new_url = preg_replace("$category", "", absoluteurl(<url>), 1);

but it fails...

Answer 1

You can use a backreference:

<?php
$str = 'http://example.com/laptop/laptop-hp-probook-101';
//must be http://example.com/laptop/hp-probook-101
$str = preg_replace('/\/(.*?)\/\1-/', '/$1/', $str);
print $str;

Output:

http://example.com/laptop/hp-probook-101