我做了下面的预匹配,以获取包含频道,生活方式频道或电子竞技频道的href,但除正确的数组外,它还返回一个空数组。我想我的表情有问题
$re = '/(?!<a href=")(?=(\/(?|channels|lifestyle-channels|esports-channels)\/[a-z 0-9-\_]{1,}))/m';
$str = '<div class="thumb-block "><div class="thumb-inside"><div class="thumb"><a href="/video55783515222/12/best_ronaldinho_plays"><img src="lightbox-blank.gif" data-src="12.jpg" data-idcdn="10" /></a></div><span class="video-hd-mark">1080p</span></div><div class="thumb-under"><p class="title"><a href="/video55783515/13/big_tips_12" title="Tips #12">Tips #12</a></p><p class="metadata"><span class="bg"><span class="duration">26 min</span><a href="/channels/tips_12"><span class="name">Tips #12</span></a><span class="text-disabled"> 20 mins ago</span></span></p></div></div>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($ matches);
结果
array(1) {
[0]=>
array(2) {
[0]=>
string(0) ""
[1]=>
string(17) "/channels/tips_12"
}
}
我想要什么
array(1) {
[0]=>
array(1) {
[0]=>
string(17) "/channels/tips_12"
}
}
尝试(?<!<a[ ]href=")/(?|channels|lifestyle-channels|esports-channels)/[a-z 0-9\-\_]+
一些笔记
(?!B)(?=A)
将始终匹配A
(?=())
和捕获组。这将导致匹配变量组0具有一个值。