从任何 YouTube URL 获取 YouTube 视频 ID 的 RegEx 模式

This PHP function will NOT properly obtain the ID in case 1, but will in case 2. Case 1 is very common, where ANYTHING can come behind the YouTube ID.

/**
 * get YouTube video ID from URL
 *
 * @param string $url
 * @return string YouTube video id or FALSE if none found. 
 */
function youtube_id_from_url($url) {
    $pattern = 
        '%^# Match any YouTube URL
        (?:https?://)?  # Optional scheme. Either http or https
        (?:www.)?      # Optional www subdomain
        (?:             # Group host alternatives
          youtu.be/    # Either youtu.be,
        | youtube.com  # or youtube.com
          (?:           # Group path alternatives
            /embed/     # Either /embed/
          | /v/         # or /v/
          | /watch?v=  # or /watch?v=
          )             # End path alternatives.
        )               # End host alternatives.
        ([w-]{10,12})  # Allow 10-12 for 11 char YouTube id.
        $%x'
        ;
    $result = preg_match($pattern, $url, $matches);
    if (false !== $result) {
        return $matches[1];
    }
    return false;
}

我的想法是，必须有一种方法可以让我只查找v="，无论它位于 URL 的哪个位置，然后获取后面的字符.以这种方式，不需要复杂的 RegEx.这是离谱吗?对起点有什么想法吗?

if (preg_match('/youtube.com/watch?v=([^&?/]+)/', $url, $id)) {
  $values = $id[1];
} else if (preg_match('/youtube.com/embed/([^&?/]+)/', $url, $id)) {
  $values = $id[1];
} else if (preg_match('/youtube.com/v/([^&?/]+)/', $url, $id)) {
  $values = $id[1];
} else if (preg_match('/youtu.be/([^&?/]+)/', $url, $id)) {
  $values = $id[1];
}
else if (preg_match('/youtube.com/verify_age?next_url=/watch%3Fv%3D([^&?/]+)/', $url, $id)) {
    $values = $id[1];
} else {   
// not an youtube video
}