function parser(url){
    var regExp = /^.*((youtu.be\/)|(v\/)|(\/u\/\w\/)|(embed\/)|(watch\/)|(\?v=|\&v=))([^#\&\?]*).*/;
    var match = url.match(regExp);
    if (match && match[8].length==11){
            alert('OK');
    }else{
            alert('BAD');
    }
}

测试:

https://www.youtube.com/embed/vDoO_bNw7fc - attention first symbol «v» in «vDoO_bNw7fc»

http://www.youtube.com/user/dreamtheater#p/u/1/oTJRivZTMLs
https://youtu.be/oTJRivZTMLs?list=PLToa5JuFMsXTNkrLJbRlB--76IAOjRM9b
http://www.youtube.com/watch?v=oTJRivZTMLs&feature=youtu.be
https://youtu.be/oTJRivZTMLs
http://youtu.be/oTJRivZTMLs&feature=channel
http://www.youtube.com/ytscreeningroom?v=oTJRivZTMLs
http://www.youtube.com/embed/oTJRivZTMLs?rel=0
http://youtube.com/v/oTJRivZTMLs&feature=channel
http://youtube.com/v/oTJRivZTMLs&feature=channel
http://youtube.com/vi/oTJRivZTMLs&feature=channel
http://youtube.com/?v=oTJRivZTMLs&feature=channel
http://youtube.com/?feature=channel&v=oTJRivZTMLs
http://youtube.com/?vi=oTJRivZTMLs&feature=channel
http://youtube.com/watch?v=oTJRivZTMLs&feature=channel
http://youtube.com/watch?vi=oTJRivZTMLs&feature=channel

Python3版本:

import re

def get_youtube_id(url):
   match = re.match('^.*((youtu.be\/)|(v\/)|(\/u\/\w\/)|(embed\/)|(watch\?))?\?v?=?(?P<id>\w*).*', url);
   return match.group('id')

如果你想在shell/bash/zsh/fish脚本中包含它，下面是如何做到的:

echo -n "$YOUTUBE_URL" | python -c "import re; import sys; m = re.match('^.*((youtu.be\/)|(v\/)|(\/u\/\w\/)|(embed\/)|(watch\?))?\?v?=?(?P<id>\w*).*', sys.stdin.read()); sys.stdout.write(m.group('id'))"

例子:

echo -n "https://www.youtube.com/watch/?v=APYVWYHS654" | python -c "import re; import sys; m = re.match('^.*((youtu.be\/)|(v\/)|(\/u\/\w\/)|(embed\/)|(watch\?))?\?v?=?(?P<id>\w*).*', sys.stdin.read()); sys.stdout.write(m.group('id'))"  

APYVWYHS654

如果有人需要Kotlin中的完美函数来节省他们的时间。希望这能有所帮助

fun extractYTId(ytUrl: String?): String? {
    var vId: String? = null
    val pattern = Pattern.compile(
        "^https?://.*(?:youtu.be/|v/|u/\\w/|embed/|watch?v=)([^#&?]*).*$",
        Pattern.CASE_INSENSITIVE
    )
    val matcher = pattern.matcher(ytUrl)
    if (matcher.matches()) {
        vId = matcher.group(1)
    }
    return vId
}

稍微严格一点的版本:

^https?://(?:www\.)?youtu(?:\.be|be\.com)/(?:\S+/)?(?:[^\s/]*(?:\?|&)vi?=)?([^#?&]+)

测试:

http://www.youtube.com/user/dreamtheater#p/u/1/oTJRivZTMLs
https://youtu.be/oTJRivZTMLs?list=PLToa5JuFMsXTNkrLJbRlB--76IAOjRM9b
http://www.youtube.com/watch?v=oTJRivZTMLs&feature=youtu.be
https://youtu.be/oTJRivZTMLs
http://youtu.be/oTJRivZTMLs&feature=channel
http://www.youtube.com/ytscreeningroom?v=oTJRivZTMLs
http://www.youtube.com/embed/oTJRivZTMLs?rel=0
http://youtube.com/v/oTJRivZTMLs&feature=channel
http://youtube.com/v/oTJRivZTMLs&feature=channel
http://youtube.com/vi/oTJRivZTMLs&feature=channel
http://youtube.com/?v=oTJRivZTMLs&feature=channel
http://youtube.com/?feature=channel&v=oTJRivZTMLs
http://youtube.com/?vi=oTJRivZTMLs&feature=channel
http://youtube.com/watch?v=oTJRivZTMLs&feature=channel
http://youtube.com/watch?vi=oTJRivZTMLs&feature=channel

你可以点击共享按钮并复制缩短URL。 例如: 这个YouTube视频的网址是https://www.youtube.com/watch?v=3R0fzCw3amM 但如果你点击分享按钮并复制缩短URL，你会得到这个https://youtu.be/3R0fzCw3amM

在c#中，它看起来是这样的:

public static string GetYouTubeId(string url) {
    var regex = @"(?:youtube\.com\/(?:[^\/]+\/.+\/|(?:v|e(?:mbed)?|watch)\/|.*[?&]v=)|youtu\.be\/)([^""&?\/ ]{11})";

    var match = Regex.Match(url, regex);

    if (match.Success)
    {
        return match.Groups[1].Value;
    }

    return url;
  }

请随意修改。