[英]Multiline regex issue in PHP
Consider the code below, why it is not working? 考虑下面的代码,为什么它不起作用?
<?php
$str = "
<h4>
title
</h4>
";
$result = preg_match_all ('/<h4>([\d\D])<\/h4>/mi', $str, $matches);
var_dump($matches);
You probably meant 你可能意味着
$str = "
<h4>
title
</h4>
";
$result = preg_match_all ('/<h4>(.+?)<\/h4>/si', $str, $matches);
var_dump($matches);
The regex you applied, '/<h4>([\\d\\D])<\\/h4>/mi'
, means "Match an opening h4, one character that's either a digit or not a digit, and a closing h4." 您应用的正则表达式
'/<h4>([\\d\\D])<\\/h4>/mi'
意思是“匹配一个开头h4, 一个数字或非数字字符和一个结尾h4。 “ But you have plenty of characters to match, so you need to specify a quantifier ("more than one", +
). 但是您要匹配的字符很多,因此需要指定一个量词(“多个”,
+
)。 Update: you need a non-greedy quantifier, +?
更新:您需要一个非贪婪的量词,
+?
, if you have more than one h4 (very likely!) And the class [\\d\\D]
can be reduced to "any character", .
,如果您有多个h4(很有可能!),并且类
[\\d\\D]
可以简化为“任何字符”, .
. 。 One more point: you need to use
/s
instead of /m
to get the behaviour you want. 还有一点:您需要使用
/s
而不是/m
来获得所需的行为。
This will probably include the newlines in your match! 这可能包括您的比赛中的换行符!
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