Preg_replace第一个匹配模式包括斜杠

Question

如何在字符串内容"/"

时删除第一个模式匹配

$a = "abc/def";
$b = "abc/def/ghi/abc/def";
$result = "/ghi/abc/def"; when replace with "abc/def" only look for the fist match

I try this but is not work.
$x  = preg_replace('/'.$a.'/', '', $b, 1);

Answer 1

您必须记住，preg_replace的第一个参数是RegEx模式，因此您不能将任何字符串传递给它。

首先需要用preg_quote

函数转义所有regex字符

试题:

$a = "abc/def";
$b = "abc/def/ghi/abc/def";
$pattern = preg_quote($a, '/'); // second argument allows us to escape delimiter chars, too
$x  = preg_replace("/$pattern/", '', $b, 1);