如何从字符串中删除特殊字符? [英] How to remove special characters from a string?

问题描述

我想删除特殊字符，例如:

I want to remove special characters like:

- + ^ . : ,

来自使用 Java 的字符串.

from an String using Java.

推荐答案

这取决于你定义的特殊字符，但试试replaceAll(...):

That depends on what you define as special characters, but try replaceAll(...):

String result = yourString.replaceAll("[-+.^:,]","");

请注意，^ 字符不能是列表中的第一个字符，因为您要么必须对其进行转义，要么表示除这些字符外的任何字符".

Note that the ^ character must not be the first one in the list, since you'd then either have to escape it or it would mean "any but these characters".

另一个注意事项:- 字符必须是列表中的第一个或最后一个，否则您必须对其进行转义或定义一个范围(例如 :-, 表示: 到 , 范围内的所有字符.

Another note: the - character needs to be the first or last one on the list, otherwise you'd have to escape it or it would define a range ( e.g. :-, would mean "all characters in the range : to ,).

因此，为了保持一致性而不依赖于字符定位，您可能希望对正则表达式中具有特殊含义的所有字符进行转义(以下列表不完整，因此请注意其他字符，例如 (, {, $ 等):

So, in order to keep consistency and not depend on character positioning, you might want to escape all those characters that have a special meaning in regular expressions (the following list is not complete, so be aware of other characters like (, {, $ etc.):

String result = yourString.replaceAll("[\-\+\.\^:,]","");

如果你想去掉所有的标点符号，试试这个正则表达式:p{P}p{S}(请记住，在 Java 字符串中，你必须转义反斜杠:"\p{P}\p{S}").

If you want to get rid of all punctuation and symbols, try this regex: p{P}p{S} (keep in mind that in Java strings you'd have to escape back slashes: "\p{P}\p{S}").

第三种方法可能是这样的，如果你能准确地定义你的字符串中应该留下什么:

A third way could be something like this, if you can exactly define what should be left in your string:

String  result = yourString.replaceAll("[^\w\s]","");

这意味着:替换所有不是单词字符(在任何情况下为 a-z，0-9 或 _)或空格的所有内容.

This means: replace everything that is not a word character (a-z in any case, 0-9 or _) or whitespace.

请注意，还有一些其他模式可能会有所帮助.但是，我无法全部解释它们，因此请查看 regular-expressions.info 的参考部分.

please note that there are a couple of other patterns that might prove helpful. However, I can't explain them all, so have a look at the reference section of regular-expressions.info.

这是 Ray 建议的定义允许的字符"方法的限制较少的替代方法:

Here's less restrictive alternative to the "define allowed characters" approach, as suggested by Ray:

String  result = yourString.replaceAll("[^\p{L}\p{Z}]","");

正则表达式匹配任何语言中不是字母和分隔符(空格、换行符等)的所有内容.请注意，您不能使用 [P{L}P{Z}] (大写 P 表示没有该属性)，因为这意味着所有不是字母的东西空格"，几乎匹配所有内容，因为字母不是空格，反之亦然.

The regex matches everything that is not a letter in any language and not a separator (whitespace, linebreak etc.). Note that you can't use [P{L}P{Z}] (upper case P means not having that property), since that would mean "everything that is not a letter or not whitespace", which almost matches everything, since letters are not whitespace and vice versa.

关于 Unicode 的其他信息

由于可能的编码方式不同(作为单个代码点或代码点的组合)，某些 unicode 字符似乎会导致问题.请参阅regular-expressions.info了解更多信息.

Some unicode characters seem to cause problems due to different possible ways to encode them (as a single code point or a combination of code points). Please refer to regular-expressions.info for more information.

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