正则表达式.NET拆分 [英] regex .net split

问题描述

我可以分割字符串为两个基础上2位：

I can split a string into two based on 2 spaces:

string Line = "1  2";

Regex.Split(Line, "  ");

=> 1,2

=> 1, 2

我想补充一个例外。仅当如本例所示'通过[]未括'分割

I would like to add an exception. Only split if 'not enclosed by [ ]' as shown in this example.

string Line = "1  2  [1  2]";

Regex.Split(Line, "  ");

=> 1，2，[1 2]

=> 1, 2, [1 2]

我可以很轻松地通过正则表达式实现这一目标？顺便说一句，我用.NET。

Can I fairly easily achieve this via regex? By the way, I use .NET.

推荐答案

您可以使用一个前瞻，断言没有结束] 下一开幕之前 [或字符串的结尾：

You could use a lookahead, that asserts that there is no closing ] before the next opening [ or the end of the string:

Regex.Split(Line, @"[ ]+(?![^\[\]]*\])");

这将失败你，如果你有嵌套 [...] 结构虽然。需要注意的是超前是不实际的比赛的一部分，它只检查接下来无需消耗任何东西。里面的前瞻我用 [^ \ [\] 这是一个否定的字符类，除了匹配任何类型的括号中的任何字符。

This will fail you if you have nested [...] structures though. Note that the lookahead is not part of the actual match, it just checks what follows without consuming anything. Inside the lookahead I used [^\[\]] which is a negated character class, matching any character except for any kind of square bracket.

另外请注意，这种分裂在1个或多个空格。如果你想需要至少两个，替换 [] + 与 [] {2} ，如果你想整整两个与 [] {2} 。

Also note that this splits on 1 or more spaces. If you want to require at least two, replace [ ]+ with [ ]{2,} and if you want exactly two with [ ]{2}.

进一步阅读lookarounds。

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