regex - 如何使用正则表达式匹配 X 和 Y 之间的数字？

Question

我想用 RegEx 匹配 X 和 Y 之间的数字。这可能吗？
([0-9]+) 将匹配任何数字，我该怎么做才能匹配 110 和 2234 之间的数字？

Answer 1

根据 Generate a Regular Expression to Match an Arbitrary Numeric Range ，并在 Regex_For_Range 为您的示例生成这样的正则表达式后:

\b0*(1[1-9][0-9]|[2-9][0-9]{2}|1[0-9]{3}|2[01][0-9]{2}|22[0-2][0-9]|223[0-4])\b

会做的伎俩。

该过程将是(仍然遵循该正则表达式生成器):

First, break into equal length ranges:

110 - 999
1000 - 2234

Second, break into ranges that yield simple regexes:

110 - 199
200 - 999
1000 - 1999
2000 - 2199
2200 - 2229
2230 - 2234

Turn each range into a regex:

1[1-9][0-9]
[2-9][0-9]{2}
1[0-9]{3}
2[01][0-9]{2}
22[0-2][0-9]
223[0-4]

Collapse adjacent powers of 10: 1[1-9][0-9] [2-9][0-9]{2} 1[0-9]{3} 2[01][0-9]{2} 22[0-2][0-9] 223[0-4]

Combining the regexes above yields:

0*(1[1-9][0-9]|[2-9][0-9]{2}|1[0-9]{3}|2[01][0-9]{2}|22[0-2][0-9]|223[0-4])

Next we'll try factoring out common prefixes using a tree:
Parse into tree based on regex prefixes:

. 1 [1-9] [0-9]
+ [0-9]{3}
+ [2-9] [0-9]{2}
+ 2 [01] [0-9]{2}
+ 2 [0-2] [0-9]
+ 3 [0-4]

Turning the parse tree into a regex yields:

0*(1([1-9][0-9]|[0-9]{3})|[2-9][0-9]{2}|2([01][0-9]{2}|2([0-2][0-9]|3[0-4])))

We choose the shorter one as our result.

\b0*(1[1-9][0-9]|[2-9][0-9]{2}|1[0-9]{3}|2[01][0-9]{2}|22[0-2][0-9]|223[0-4])\b