Java正则表达式删除所有非字母数字字符EXCEPT空格 [英] Java regular expression to remove all non alphanumeric characters EXCEPT spaces

问题描述

我正在尝试用Java编写正则表达式，删除段落中的所有非字母数字字符，但单词之间的空格除外。

I'm trying to write a regular expression in Java which removes all non-alphanumeric characters from a paragraph, except the spaces between the words.

这是代码我写的：

paragraphInformation = paragraphInformation.replaceAll("[^a-zA-Z0-9\s]", "");

然而，编译器给了我一条错误消息，指出s说它是非法转义字符。在我将\s添加到正则表达式的末尾之前，程序编译好了，但问题是段落中单词之间的空格被删除了。

However, the compiler gave me an error message pointing to the s saying it's an illegal escape character. The program compiled OK before I added the \s to the end of the regular expression, but the problem with that was that the spaces between words in the paragraph were stripped out.

如何修复此错误？

推荐答案

您需要双重转义 \ 字符：[^ a-zA-Z0-9 \\ s]

You need to double-escape the \ character: "[^a-zA-Z0-9\\s]"

Java会将 \s 解释为Java String转义字符，这确实是一个无效的Java转义符。通过编写 \\ ，您可以转义 \ 字符，基本上只发送一个 \ 正则表达式的字符。此 \ 然后成为正则表达式转义字符 \s 的一部分。

Java will interpret \s as a Java String escape character, which is indeed an invalid Java escape. By writing \\, you escape the \ character, essentially sending a single \ character to the regex. This \ then becomes part of the regex escape character \s.

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