C# Regex.Replace 匹配相同数量的字符 [英] C# Regex.Replace match by the same amount of characters

问题描述

我想知道如何将未知数量的等号(不少于 2...)的正则表达式匹配替换为相同数量的下划线

I like to know how to replace a regex-match of unknown amount of equal-signs, thats not less than 2... to the same amount of underscores

到目前为止我得到了这个:

So far I got this:

text = Regex.Replace(text, "(={2,})", ""); 

我应该使用什么作为第三个参数?

What should I use as the 3rd parameter ?

最好是兼容所有语言的正则表达式解决方案

Prefferably a regex solution thats compatible in all languages

推荐答案

一个不太明确的答案(在代码清晰度方面):

A much less clear answer (in term of code clarity):

text = Regex.Replace(text, "=(?==)|(?<==)=", "_");

如果连续有超过 2 个 =，那么在每个 = 处，我们都会在前面或后面找到一个 =.

If there are more than 2 = in a row, then at every =, we will find a = ahead or behind.

这仅在语言支持后视(包括 C#、Java、Python、PCRE...但不包括 JavaScript)时有效.

This only works if the language supports look-behind, which includes C#, Java, Python, PCRE... and excludes JavaScript.

但是，由于您可以在 JavaScript 中将函数传递给 String.replace 函数，因此您可以编写类似于 Alexei Levenkov 的答案的代码.实际上，Alexei Levenkov 的答案适用于多种语言(当然，Java 除外).

However, since you can pass a function to String.replace function in JavaScript, you can write code similar to Alexei Levenkov's answer. Actually, Alexei Levenkov's answer works in many languages (well, except Java).

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