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

这取决于您定义为特殊字符的内容，但请尝试 replaceAll（...）：

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

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

请注意 ^ 字符不得为列表中的第一个，因为你要么必须逃避它，要么意味着除了这些字符之外。

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： - 字符需要是列表中的第一个或最后一个，否则你必须转义它或者它将定义一个范围（例如： - ，表示范围内的所有字符：到，）。

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，您可能希望转义所有在正则表达式中具有特殊含义的字符（以下列表不完整，因此，知道其他字符，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("[\\-\\+\\.\\^:,]","");

如果你想摆脱所有的标点符号离子和符号，试试这个正则表达式： \p {P} \p {S} （请记住，在Java字符串中你必须逃避反斜杠： \\\\ {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}").

第三个方式可能是这样的，如果你可以准确定义字符串中应该保留的内容：

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：替换不是单词字符的所有内容（在任何情况下为az，0-9或_）或空白。

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

编辑：请注意，还有其他一些模式可能会有所帮助。但是，我无法解释所有这些，所以请查看 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.

正如雷建议的那样，这里的定义允许字符方法的限制性较小的替代方案：

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的所有内容，而不是分隔符（空格，换行符等） ）。请注意，您不能使用 [\P {L} \P {Z}] （大写字母P表示没有该属性），因为这意味着所有不是字母或空格的东西，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.

有关Unicode的其他信息

一些unicode字符似乎会因为编码它们的不同方式（作为单个代码点或代码点组合）而导致问题。有关更多信息，请参阅 regular-expressions.info 。

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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