正则表达式从字符串末尾开始搜索(反向) [英] Regex start searching from the end of the string (reverse)

问题描述

我有一些字符串，其中的块用下划线括起来.示例:

*Text* _word_ 这是我们每天阅读的内容._文本中的文字_可以非常具有表现力._一篇好文是你身心的愉悦_(奥斯卡·王尔德)

在上面的示例中，有三个这样的块，但数量因字符串而异.我只想匹配最后一个，即从行尾开始懒洋洋地跳过字符直到找到第一个 _ ，跳过任何后续字符直到遇到第二个 _ 并在那里停止.>

如果我们要查找字符串中的第一个块，很容易找到类似的块，但是如何找到 最后一个 块呢?

解决方案

试试看:

((?:_[^_\r\n]*){2})$

它匹配一个下划线，后跟任意数量的任何非下划线或换行符的字符，所有这些都在留置结束之前出现两次.

I have strings that have blocks enclosed in underscores in them. Example:

*Text* _word_ it is something we read every day. _Words in texts_ can be really expressive. _A nice text is a pleasure for your body and soul_ (Oscar Wilde)

In the example above there are three such blocks but the number varies from string to string. I want to match only the last one, i.e. starting from the end of the line lazily skip characters until the first _ is found, skip any following characters until encountering the second _ and stop right there.

It is easy to to find a similar block if we were looking for the very first one inside the string, but how about finding the last one?

解决方案

Have a try with:

((?:_[^_\r\n]*){2})$

It matches an underscore followed by any number of any character that is not underscore or line break, all that occurs twice before the end of lien.

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