Cheat sheet for C# regular expressions metacharacters, operators, quantifiers etc
Character
Description
\
|
Marks the next character as either a special character
or escapes a literal. For example, "n" matches the character "n". "\n" matches
a newline character. The sequence "\\" matches "\" and "\(" matches "(".
Note: double quotes may be escaped by doubling them: "<a href=""...>"
|
^
|
Depending on whether the MultiLine option is set,
matches the position before the first character in a line, or the first
character in the string. |
$
|
Depending on whether the MultiLine option is set,
matches the position after the last character in a line, or the last
character in the string. |
*
|
Matches the preceding character zero or more times. For
example, "zo*" matches either "z" or "zoo". |
+
|
Matches the preceding character one or more times. For
example, "zo+" matches "zoo" but not "z". |
?
|
Matches the preceding character zero or one time. For
example, "a?ve?" matches the "ve" in "never". |
.
|
Matches any single character except a newline character. |
(pattern)
|
Matches pattern
and remembers the match. The
matched substring can be retrieved from the resulting Matches
collection,
using Item [0]...[n]
. To match parentheses characters
( ), use "\(" or "\)". |
(?<name>pattern)
|
Matches pattern
and gives the match a name. |
(?:pattern)
|
A non-capturing group |
(?=...)
|
A positive lookahead |
(?!...)
|
A negative lookahead |
(?<=...)
|
A positive lookbehind . |
(?<!...)
|
A negative lookbehind . |
x|y
|
Matches either x
or y
. For example, "z|wood" matches "z" or "wood". "(z|w)oo" matches "zoo" or "wood". |
{n
}
|
n
is a non-negative integer. Matches exactly n
times.
For example, "o{2}" does not match the "o" in "Bob," but matches the
first two o's in "foooood". |
{n
,}
|
n
is a non-negative integer. Matches at least n
times.
For example, "o{2,}" does not match the "o" in "Bob" and matches all
the o's in "foooood." "o{1,}" is equivalent to "o+". "o{0,}" is equivalent
to "o*". |
{
n
,
m
}
|
m
and n
are non-negative integers. Matches
at least n
and at most m
times. For example, "o{1,3}" matches
the first three o's in "fooooood." "o{0,1}" is equivalent to "o?". |
[
xyz
]
|
A character set. Matches any one of the enclosed characters.
For example, "[abc]" matches the "a" in "plain". |
[^
xyz
]
|
A negative character set. Matches any character not enclosed.
For example, "[^abc]" matches the "p" in "plain". |
[
a-z
]
|
A range of characters. Matches any character in the specified
range. For example, "[a-z]" matches any lowercase alphabetic character
in the range "a" through "z". |
[^
m-z
]
|
A negative range characters. Matches any character not
in the specified range. For example, "[m-z]" matches any character not
in the range "m" through "z". |
\b
|
Matches a word boundary, that is, the position between
a word and a space. For example, "er\b" matches the "er" in "never" but
not the "er" in "verb". |
\B
|
Matches a non-word boundary. "ea*r\B" matches the "ear" in "never
early". |
\d
|
Matches a digit character. Equivalent to [0-9]. |
\D
|
Matches a non-digit character. Equivalent to [^0-9]. |
\f
|
Matches a form-feed character. |
\k
|
A back-reference to a named group. |
\n
|
Matches a newline character. |
\r
|
Matches a carriage return character. |
\s
|
Matches any white space including space, tab, form-feed,
etc. Equivalent to "[ \f\n\r\t\v]". |
\S
|
Matches any nonwhite space character. Equivalent to "[^ \f\n\r\t\v]". |
\t
|
Matches a tab character. |
\v
|
Matches a vertical tab character. |
\w
|
Matches any word character including underscore. Equivalent
to "[A-Za-z0-9_]". |
\W
|
Matches any non-word character. Equivalent to "[^A-Za-z0-9_]". |
\num
|
Matches num
, where num
is a positive
integer. A reference back to remembered matches. For example, "(.)\1" matches
two consecutive identical characters. |
\n
|
Matches n
, where n
is an octal escape
value. Octal escape values must be 1, 2, or 3 digits long. For example, "\11" and "\011" both
match a tab character. "\0011" is the equivalent of "\001" & "1".
Octal escape values must not exceed 256. If they do, only the first
two digits comprise the expression. Allows ASCII codes to be used in
regular expressions. |
\xn
|
Matches n
, where n
is a hexadecimal
escape value. Hexadecimal escape values must be exactly two digits long.
For example, "\x41" matches "A". "\x041" is equivalent to "\x04" & "1".
Allows ASCII codes to be used in regular expressions. |
\un
|
Matches a Unicode character expressed in
hexadecimal notation with exactly four numeric digits. "\u0200" matches a
space character. |
\A
|
Matches the position before the first character in a string. Not affected by the MultiLine setting |
\Z
|
Matches the position after the last character of a string. Not affected by the MultiLine setting. |
\G
|
Specifies that the matches must be consecutive, without any intervening non-matching characters. |
相关推荐
最后,"正则表达式参考文档 - Regular Expression Syntax Reference.mht"是一个完整的正则表达式语法参考手册,包含了所有可能的语法元素和操作符,是学习和查阅正则表达式语法的重要资源。 通过这个压缩包中的资料...
C# 7.0 Pocket Reference: Instant Help for C# 7.0 Programmers English | 2017 | ISBN-10: 1491988533 | 234 pages | PDF + EPUB + MOBI(conv) | 2 Mb When you need answers for programming with C# 7.0, this ...
这个压缩包文件“regular Expression”可能包含了一个用C#编写的正则表达式验证工具的源代码,该工具可以帮助开发者验证输入数据是否符合特定的格式要求。 正则表达式的基本概念: 1. 元字符:如`. ^ $ * + ? { [ ]...
Easy to browse, it’s ideal as a quick reference or as a guide to get you rapidly up to speed if you already know Java, C++, or an earlier version of C#. ☆ 出版信息:☆ [作者信息] Joseph Albahari,...
C# 7.0 Pocket Reference(Early Release) 英文mobi 本资源转载自网络,如有侵权,请联系上传者或csdn删除 本资源转载自网络,如有侵权,请联系上传者或csdn删除
这个压缩包中的"Csharp LanguageReference.pdf"很可能是微软官方发布的C#语言指南的英文版,对于学习和深入理解C#编程语言具有很高的价值。 首先,我们要了解C#的基本概念。C#的核心特性包括类、接口、继承、多态性...
C# Language Pocket Reference 大家参考一下哈
本主题将详细探讨如何使用C#的表达式(Expression)来实现对象的深拷贝。 首先,我们需要理解什么是表达式树(Expression Tree)。表达式树是一种表示代码的抽象数据结构,它能够让我们以数据的形式查看和操作代码...
一个通用的基于Regular Expression in ASP.NET进行验证的类库函数,采用C#+VS2005开发实现。
Expression自定义生成SQL,可链表、分组、排序、自定义。 Expression是一个可以将Expression表达式树解析成Transact-SQL的项目。只要调用者熟悉基本的Transact-SQL语法即可瞬间无忧开码,大大降低了学习Expression2...
《Microsoft Visual C# .NET (Core Reference) (VBL)》是关于C#编程语言核心参考的资源,针对的是.NET框架的开发环境。C#是一种面向对象的编程语言,由微软公司开发,主要用于构建Windows应用程序、Web应用以及移动...
This quick C# 7 guide is a condensed code and syntax reference to the C# programming language, updated with the latest features of C# 7.3 for .NET and Windows 10. It presents the essential C# 7 syntax...
Well-known C# expert Rod Stephens gives novice and experienced developers a comprehensive tutorial and reference to standard C#. This new title fully covers the latest C# language standard, C# 5.0, as...
C# 7.0 Pocket Reference(Early Release) 英文epub 本资源转载自网络,如有侵权,请联系上传者或csdn删除 本资源转载自网络,如有侵权,请联系上传者或csdn删除
根据给定的文件信息,我们可以提炼出关于"C# 2005 Programmer's Reference"的知识点,这本由Adrian Kingsley-Hughes和Kathie Kingsley-Hughes撰写的书籍是C#编程语言的一份详尽指南,旨在帮助程序员理解和掌握C# ...
C#是一种简单、现代、面向对象和类型安全的编程语言,由C和C++发展而来。C#牢固地植根于C和C++语言族谱中,并且会很快被C和C++程序员所熟悉。C#的目标在于把Visual Basic的高生产力和C++本身的能力结合起来。
表达式树(Expression Trees)是.NET Framework中的一个重要概念,特别是与C#语言紧密相关。表达式树允许开发者以树状结构表示代码表达式。每棵树代表一个表达式,而树的节点代表表达式中的运算符、方法调用、参数等...