限制捕获组字符数 [英] Limit number of character of capturing group

问题描述

假设我有这样的文字:"AAAA1 AAA11 AA111AA A1111 AAAAA AAAA1111".

Let's say i have this text : "AAAA1 AAA11 AA111AA A1111 AAAAA AAAA1111".

我想找到符合这 3 个条件的所有事件:
-大写字母 1 到 4 次
-数字1到4次
-最大字符数为 5

I want to find all occurrences matching these 3 criteria :
-Capital letter 1 to 4 times
-Digit 1 to 4 times
-Max number of characters to be 5

所以匹配将是:
{"AAAA1", "AAA11", "AA111", "A1111", "AAAA1"}

我试过了

([A-Z]{1,4}[0-9]{1,4}){5}

但我知道它会失败，因为它正在寻找我的团队五次.

but i knew it would fail, since it's looking for five time my group.

有没有办法将组的结果限制为 5 个字符?

Is there a way to limit result of the groups to 5 characters?

谢谢

推荐答案

您可以在检查匹配部分的模式时提前限制字符数.

You can limit the character count with a look ahead while checking the pattern with you matching part.

如果你可以用空格分割输入，你可以使用:

If you can split the input by whitespace you can use:

^(?=.{2,5}$)[A-Z]{1,4}[0-9]{1,4}$

请参阅此处的演示.

如果你不能用空格分割你可以用 (?:^| )(?=.{2,5}(?=$| ))([AZ]{1,4}[0-9]{1,4})(?=$| ) 例如，或lookbehind 或 \K 根据您的正则表达式风格进行拆分(请参阅 演示).

If you cannot split by whitespace you can use capturing group with (?:^| )(?=.{2,5}(?=$| ))([A-Z]{1,4}[0-9]{1,4})(?=$| ) for example, or lookbehind or \K to do the split depending on your regex flavor (see demo).

PREVIOUS ANSWER，错误匹配A1A1A，在@a_guest 评论后更新.

PREVIOUS ANSWER, wrongly matches A1A1A, updated after @a_guest remark.

您可以使用前瞻来检查您的模式，同时使用正则表达式的匹配部分限制字符数:

You can use a lookahead to check for your pattern, while limiting the character count with the matching part of the regex:

(?=[A-Z]{1,4}[0-9]{1,4}).{2,5}

请参阅此处的演示.

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