什么是＆QUOT;嵌套量词＆QUOT;为什么是这导致我的正则表达式失败？ [英] What is a "Nested Quantifier" and why is it causing my regex to fail?

问题描述

我有这样的正则表达式我建立和正则表达式的好友进行测试。

I have this regex I built and tested in regex buddy.

"_ [ 0-9]{10}+ {1}+[ 0-9]{10}+ {2}+[ 0-9]{6}+ {2}[ 0-9]{2}"

当我使用这个在.net C＃

When I use this in .Net C#

我收到异常

"parsing \"_ [ 0-9]{10}+ +[ 0-9]{10}+  +[ 0-9]{6}+  [ 0-9]{2}\" - Nested quantifier +."

这是什么错误呢？显然，.NET并没有像前pression。

What does this error mean? Apparently .net doesn't like the expression.

下面是正则表达式的哥们，这样你们能理解我的意图与正则表达式...

Here is the regex buddy so u can understand my intention with the regex...

_ [ 0-9]{10}+ {1}+[ 0-9]{10}+ {2}+[ 0-9]{6}+ {2}[ 0-9]{2}

Match the characters "_ " literally «_ »
Match a single character present in the list below «[ 0-9]{10}+»
   Exactly 10 times «{10}+»
   The character " " « »
   A character in the range between "0" and "9" «0-9»
Match the character " " literally « {1}+»
   Exactly 1 times «{1}+»
Match a single character present in the list below «[ 0-9]{10}+»
   Exactly 10 times «{10}+»
   The character " " « »
   A character in the range between "0" and "9" «0-9»
Match the character " " literally « {2}+»
   Exactly 2 times «{2}+»
Match a single character present in the list below «[ 0-9]{6}+»
   Exactly 6 times «{6}+»
   The character " " « »
   A character in the range between "0" and "9" «0-9»
Match the character " " literally « {2}»
   Exactly 2 times «{2}»
Match a single character present in the list below «[ 0-9]{2}»
   Exactly 2 times «{2}»
   The character " " « »
   A character in the range between "0" and "9" «0-9»

在短...

什么是嵌套量词？

推荐答案

.NET的抱怨 + 在 {N} 风格的量词，因为它没有任何意义。 {N} 表示正好给定组正赛。 + 表示匹配一个或多个特定组。删除 + 的，它会编译罚款。

.NET is complaining about the + after the {n} style quantifier as it doesn't make any sense. {n} means match exactly n of a given group. + means match one or more of a given group. Remove the +'s and it'll compile fine.

"_ [ 0-9]{10} {1}[ 0-9]{10} {2}[ 0-9]{6} {2}[ 0-9]{2}"

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