youtube - youtube preg_replace链接不同

Question

我将此代码用于preg_replace youtube代码，但是我遇到了问题，这是我的代码

// replace video Youtube to thumbnail       
$string     = array('http://youtube.com/watch?v=slBEtqC_JsI', 'https://youtu.be/bOxza0rLv1o');
//fix the '/' in the end of url
$string = trim($string, '/');
$search = array();
$search[0] = '~(?:https://(?:www\.)?youtube\.com\/watch\?v=)?([a-zA-Z0-9_\-+?:]+)~';
$search[1] = '~(?:https://(?:www\.)?youtu\.be\/)?([a-zA-Z0-9_\-+?:]+)~';
$replace = array();
$replace[1]    = 'https://i.ytimg.com/vi/$1/hqdefault.jpg';   
$replace[0]   = 'https://i.ytimg.com/vi/$1/hqdefault.jpg'; 
$soc_youtube = preg_replace($search,$replace,$string);

该代码不会更改字符串，输出将是

https://i.ytimg.com/vi/https:/hqdefault.jpg//https://i.ytimg.com/vi/i/hqdefault.jpg.https://i.ytimg.com/vi/ytimg/hqdefault.jpg.https://i.ytimg.com/vi/com/hqdefault.jpg/https://i.ytimg.com/vi/vi/hqdefault.jpg/https://i.ytimg.com/vi/https:/hqdefault.jpg/https://i.ytimg.com/vi/hqdefault/hqdefault.jpg.https://i.ytimg.com/vi/jpg/hqdefault.jpg//https://i.ytimg.com/vi/https:/hqdefault.jpg//https://i.ytimg.com/vi/i/hqdefault.jpg.https://i.ytimg.com/vi/ytimg/hqdefault.jpg.https://i.ytimg.com/vi/com/hqdefault.jpg/https://i.ytimg.com/vi/vi/hqdefault.jpg/https://i.ytimg.com/vi/youtu/hqdefault.jpg/https://i.ytimg.com/vi/hqdefault/hqdefault.jpg.https://i.ytimg.com/vi/jpg/hqdefault.jpg.https://i.ytimg.com/vi/https:/hqdefault.jpg//https://i.ytimg.com/vi/i/hqdefault.jpg.https://i.ytimg.com/vi/ytimg/hqdefault.jpg.https://i.ytimg.com/vi/com/hqdefault.jpg/https://i.ytimg.com/vi/vi/hqdefault.jpg/https://i.ytimg.com/vi/be/hqdefault.jpg/https://i.ytimg.com/vi/hqdefault/hqdefault.jpg.https://i.ytimg.com/vi/jpg/hqdefault.jpg/https://i.ytimg.com/vi/https:/hqdefault.jpg//https://i.ytimg.com/vi/i/hqdefault.jpg.https://i.ytimg.com/vi/ytimg/hqdefault.jpg.https://i.ytimg.com/vi/com/hqdefault.jpg/https://i.ytimg.com/vi/vi/hqdefault.jpg/https://i.ytimg.com/vi/bOxza0rLv1o/hqdefault.jpg/https://i.ytimg.com/vi/hqdefault/hqdefault.jpg.https://i.ytimg.com/vi/jpg/hqdefault.jpg);

有人可以帮助我吗？
谢谢你的帮助

Answer 1

您可以使用

'~(?:https?://(?:www\.)?youtu(?:be\.com/watch\?v=|\.be/))?([a-zA-Z0-9_\-+?:]+)/?~'

参见 regex demo。图案细节:

(?:-第一个交替组的开始:

https?://(?:www\.)?youtu-https://或https://，然后是可选的www.子字符串，然后是youtu子字符串

(?:-第二个交替组的开始:

be\.com/watch\?v=-be.com/watch?v=子字符串

|-或

\.be/-.be/子字符串

)-第二个替代组

的结尾

)?-1或0次

([a-zA-Z0-9_\-+?:]+)-组1:一个或多个单词，-，+，?或:字符

/?-可选的/

参见 PHP demo online:

$string = array('http://youtube.com/watch?v=slBEtqC_JsI', 'https://youtu.be/bOxza0rLv1o', 'http://youtube.com/watch?v=slBEtqC_JSJ/');
$search = '~(?:https?://(?:www\.)?youtu(?:be\.com/watch\?v=|\.be/))?([a-zA-Z0-9_+?:-]+)/?~';
$replace = 'https://i.ytimg.com/vi/$1/hqdefault.jpg';   
$soc_youtube = preg_replace($search,$replace,$string);
print_r($soc_youtube);

输出:

Array
(
    [0] => https://i.ytimg.com/vi/slBEtqC_JsI/hqdefault.jpg
    [1] => https://i.ytimg.com/vi/bOxza0rLv1o/hqdefault.jpg
    [2] => https://i.ytimg.com/vi/slBEtqC_JSJ/hqdefault.jpg
)