问题描述
我正在尝试验证我的应用程序的 YouTube 网址.
I'm trying to validate YouTube URLs for my application.
到目前为止，我有以下几点:
So far I have the following:
// Set the youtube URL
$youtube_url = "www.youtube.com/watch?v=vpfzjcCzdtCk";
if (preg_match("/((http://){0,}(www.){0,}(youtube.com){1} || (youtu.be){1}(/watch?v=[^s]){1})/", $youtube_url) == 1)
{
echo "Valid";
else
{
echo "Invalid";
}
我希望验证 Youtube 网址的以下变体:
I wish to validate the following variations of Youtube Urls:
- 有和没有 http://
- 有和没有 www.
- 使用网址 youtube.com 和 youtu.be
- 必须有/watch?v=
- 必须具有唯一的视频字符串(在上面的示例中为vpfzjcCzdtCk")
但是，我认为我的逻辑不正确，因为出于某种原因它返回 true 用于:www.youtube.co/watch?v=vpfzjcCzdtCk(注意我用 .co 而不是 .com 写错了)
However, I don't think I've got my logic right, because for some reason it returns true for: www.youtube.co/watch?v=vpfzjcCzdtCk (Notice I've written it incorrectly with .co and not .com)
推荐答案
在你的这个正则表达式中有很多冗余(还有 倾斜牙签综合症).不过，这应该会产生结果:
There are a lot of redundancies in this regular expression of yours (and also, the leaning toothpick syndrome). This, though, should produce results:
$rx = '~
^(?:https?://)? # Optional protocol
(?:www[.])? # Optional sub-domain
(?:youtube[.]com/watch[?]v=|youtu[.]be/) # Mandatory domain name (w/ query string in .com)
([^&]{11}) # Video id of 11 characters as capture group 1
~x';
$has_match = preg_match($rx, $url, $matches);
// if matching succeeded, $matches[1] would contain the video ID
一些注意事项:
- 使用波浪号
~作为分隔符，避免 LTS - 使用
[.]而不是.来提高视觉易读性并避免 LTS.(特殊"字符 - 例如点.- 在字符类中无效(方括号内)) - 为了使正则表达式更可读"，您可以使用
x修饰符(这有进一步的含义；请参阅 关于模式修饰符的文档)，它还允许在正则表达式中添加注释 - 可以使用非捕获组来抑制捕获:
(?:.这使表达式更有效.)
- use the tilde character
~as delimiter, to avoid LTS - use
[.]instead of.to improve visual legibility and avoid LTS. ("Special" characters - such as the dot.- have no effect in character classes (within square brackets)) - to make regular expressions more "readable" you can use the
xmodifier (which has further implications; see the docs on Pattern modifiers), which also allows for comments in regular expressions - capturing can be suppressed using non-capturing groups:
(?: <pattern> ). This makes the expression more efficient.
或者，要从(或多或少完整的)URL 中提取值，您可能需要使用 parse_url():
Optionally, to extract values from a (more or less complete) URL, you might want to make use of parse_url():
$url = 'http://youtube.com/watch?v=VIDEOID';
$parts = parse_url($url);
print_r($parts);
输出:
Array
(
[scheme] => http
[host] => youtube.com
[path] => /watch
[query] => v=VIDEOID
)
验证域名和提取视频 ID 留给读者作为练习.
Validating the domain name and extracting the video ID is left as an exercise to the reader.
我屈服于下面的评论战；感谢 Toni Oriol，正则表达式现在也适用于短 (youtu.be) 网址.
I gave in to the comment war below; thanks to Toni Oriol, the regular expression now works on short (youtu.be) URLs as well.
这篇关于使用正则表达式验证 Youtube URL的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！