This script should detect the last portion in the full path, and if it is stackoverflow output ok

$current_url = $_SERVER['REQUEST_URI'];

$current_url_arr = explode('/',$current_url);
$count = count($current_url_arr);

if($current_url_arr[$count-2] == 'stackoverflow'){
    echo 'ok';
}
else {
    echo 'not ok';
}

Example 1: www.myserver.ext/something/else/stackoverflow/ Output: ok

Example 2: www.myserver.ext/something/else/stackoverflow Output: not ok

Example 3: www.myserver.ext/something/else/stackoverflow/foo Output: not ok

I hope that you understand the idea. This script works fine, but I'm wondering if there is any better, elegant way to read last portion of URL?