Get Youtube ID from URL

gistfile1.txt

function YouTubeID(){
      if($youtube_url = $this->YouTubeLink){
        
        $url = parse_url($youtube_url);

        if( $url['host'] !== 'youtube.com' &&
            $url['host'] !== 'www.youtube.com'&&
            $url['host'] !== 'youtu.be'&&
            $url['host'] !== 'www.youtu.be')
        return '';
    
        if( $url['host'] === 'youtube.com' || $url['host'] === 'www.youtube.com' ) :
            parse_str(parse_url($youtube_url, PHP_URL_QUERY), $query_string);
            return $query_string["v"];
        endif;
    
        $youtube_id = substr( $url['path'], 1 );
        if( strpos( $youtube_id, '/' ) )
            $youtube_id = substr( $youtube_id, 0, strpos( $youtube_id, '/' ) );
    
        return $youtube_id;
      }else{
        return false;
      }
      
    }