如何从此网址中提取YouTube ID？
https%253A%252F%252Fwww.youtube.com%252Fwatch%253Fv%253Dnn5hCEMyE-E
我试过这个正则表达式:
$url = $_GET["q"];
preg_match("/^(?:http(?:s)?:\/\/)?(?:www\.)?(?:m\.)?(?:youtu\.be\/|youtube\.com\/(?:(?:watch)?\?(?:.*&)?v(?:i)?=|(?:embed|v|vi|user)\/))([^\?&\"'>]+)/", $url, $matches);