regex - 替换包含问号的字符串

Question

这是我的代码:

$html = 'Is this a question? Maybe.';
$old = 'question?';
$new = 'reply?';

$html =~ s/$old/$new/g;
print $html; exit;

输出是:

Is this a reply?? Maybe.

期望的输出:

Is this a reply? Maybe.

我做错了什么？

Answer 1

使用quotemeta转义 ?:

$html = 'Is this a question? Maybe.';
$old = quotemeta 'question?';
$new = 'reply?';

$html =~ s/$old/$new/g;
print $html; exit;