Character |
Description |
\ |
Mark the next character as a special character, a literal character, or a backward reference, or an octal escape character. For example, 'n' matches the character "n ". '\ N' matches a line break. The sequence '\' matches "\" and "\ (" matches "(". |
^ |
Matches the start position of the input string. If the Multiline attribute of the RegExp object is set, ^ matches the position after '\ n' or' \ R. |
$ |
Matches the end position of the input string. If the Multiline attribute of the RegExp object is set, $ also matches the position before '\ n' or' \ R. |
* |
Matches the previous subexpression zero or multiple times. For example, zo * can match "z" and "zoo ". * Is equivalent to {0 ,}. |
+ |
Match the previous subexpression once or multiple times. For example, 'Zo + 'can match "zo" and "zoo", but cannot match "z ". + Is equivalent to {1 ,}. |
? |
Match the previous subexpression zero or once. For example, "do (es )? "Can match" do "in" do "or" does ".? It is equivalent to {0, 1 }. |
{N} |
NIs a non-negative integer. MatchedNTimes. For example, 'O {2} 'cannot match 'O' in "Bob", but can match two o in "food. |
{N,} |
NIs a non-negative integer. At least matchNTimes. For example, 'O {2,} 'cannot match 'O' in "Bob", but can match all o in "foooood. 'O {1,} 'is equivalent to 'o + '. 'O {0,} 'is equivalent to 'o *'. |
{N,M} |
MAndNAll are non-negative integers, whereN<=M. Least matchNTimes and most matchingMTimes. For example, "o {1, 3}" matches the first three o in "fooooood. 'O {0, 1} 'is equivalent to 'o? '. Note that there must be no space between a comma and two numbers. |
? |
When this character is followed by any other delimiter (*, + ,?, {N},{N,},{N,M}) The matching mode is not greedy. The non-Greedy mode matches as few searched strings as possible, while the default greedy mode matches as many searched strings as possible. For example, for strings "oooo", 'O ++? 'Will match a single "o", and 'O +' will match all 'O '. |
. |
Matches any single character except "\ n. To match any character including '\ n', use a pattern like' [. \ n. |
(Pattern) |
MatchPatternAnd obtain the matching. The obtained match can be obtained from the generated Matches set. It is used in VBScript.SubMatchesSet, which is used in JScript$0...$9Attribute. To match the parentheses, use '\ (' or '\)'. |
(? :Pattern) |
MatchPatternBut does not get the matching result, that is, this is a non-get match and is not stored for future use. This is useful when you use the "or" character (|) to combine each part of a pattern. For example, 'industr (? : Y | ies) is a simpler expression than 'industry | industries. |
(? =Pattern) |
Forward pre-query, in any matchPatternTo start from the string. This is a non-get match, that is, the match does not need to be obtained for future use. For example, 'windows (? = 95 | 98 | NT | 2000) 'can match "Windows" in "Windows 2000", but cannot match "Windows" in "Windows 3.1 ". Pre-query does not consume characters, that is, after a match occurs, the next matching search starts immediately after the last match, instead of starting after the pre-query characters. |
(?!Pattern) |
Negative pre-query, in any MismatchPatternTo start from the string. This is a non-get match, that is, the match does not need to be obtained for future use. For example, 'windows (?! 95 | 98 | NT | 2000) 'can match "Windows" in "Windows 3.1", but cannot match "Windows" in "Windows 2000 ". Pre-query does not consume characters. That is to say, after a match occurs, the next matching search starts immediately after the last match, instead of starting after the pre-query characters. |
X|Y |
MatchXOrY. For example, 'z | food' can match "z" or "food ". '(Z | f) ood' matches "zood" or "food ". |
[Xyz] |
Character Set combination. Match any character in it. For example, '[abc]' can match 'A' in "plain '. |
[^Xyz] |
Negative value character set combination. Match any character not included. For example, '[^ abc]' can match 'p' in "plain '. |
[A-z] |
Character range. Matches any character in the specified range. For example, '[a-z]' can match any lowercase letter in the range of 'A' to 'Z. |
[^A-z] |
Negative character range. Matches any character that is not within the specified range. For example, '[^ a-z]' can match any character that is not in the range of 'A' to 'Z. |
\ B |
MatchWord boundaryThat is, the position between a word and a space. For example, 'er \ B 'can match 'er' in "never", but cannot match 'er 'in "verb '. |
\ B |
Match non-word boundary. 'Er \ B 'can match 'er' in "verb", but cannot match 'er 'in "never '. |
\ CX |
MatchingXThe specified control character. For example, \ cM matches a Control-M or carriage return character.XMust be a A-Z or one of a-z. Otherwise, c is treated as an original 'C' character. |
\ D |
Match a numeric character. It is equivalent to [0-9]. |
\ D |
Match a non-numeric character. It is equivalent to [^ 0-9]. |
\ F |
Match a form feed. It is equivalent to \ x0c and \ cL. |
\ N |
Match A linefeed. It is equivalent to \ x0a and \ cJ. |
\ R |
Match a carriage return. It is equivalent to \ x0d and \ cM. |
\ S |
Matches any blank characters, including spaces, tabs, and page breaks. It is equivalent to [\ f \ n \ r \ t \ v]. |
\ S |
Match any non-blank characters. It is equivalent to [^ \ f \ n \ r \ t \ v]. |
\ T |
Match a tab. It is equivalent to \ x09 and \ cI. |
\ V |
Match a vertical tab. It is equivalent to \ x0b and \ cK. |
\ W |
Match any word characters that contain underscores. It is equivalent to '[A-Za-z0-9 _]'. |
\ W |
Match any non-word characters. It is equivalent to '[^ A-Za-z0-9 _]'. |
\ Xn |
MatchN, WhereNIt is a hexadecimal escape value. The hexadecimal escape value must be determined by the length of two numbers. For example, '\ x41' matches "". '\ X041' is equivalent to '\ x04' & "1 ". The regular expression can be ASCII encoded. |
\Num |
MatchNum, WhereNumIs a positive integer. References to the obtained matching. For example, '(.) \ 1' matches two consecutive identical characters. |
\N |
Identifies an octal escape value or a backward reference. If \NAt leastNObtained subexpressionsNIs backward reference. Otherwise, ifNIs an octal digit (0-7 ),NIt is an octal escape value. |
\Nm |
Identifies an octal escape value or a backward reference. If \NmAt leastNmTo obtain the subexpressionNmIs backward reference. If \NmAt leastNNIs followed by textM. If none of the preceding conditions are metNAndMAll are Octal numbers (0-7), then \NmMatch the octal escape ValueNm. |
\NmL |
IfNIt is an octal digit (0-3) andMAndLIf the values are Octal numbers (0-7), the octal escape value is matched.Nml. |
/I |
Make the regular expression not case sensitive ,(? -I) Disable case insensitive. (? I) te (? -I) st should match TEst, but cannot match teST or TEST. |
/S |
Enable "single line mode", that is, the dot "." matches the New Line Character |
/M |
Enable "multiline mode", that is, "^" and "$" match the front and back positions of the new line character. |
^ [0-9] * $ |
Only numbers can be entered |
^ \ D {n} $ |
Only numbers with n digits can be entered. |
^ \ D {n,} $ |
Only numbers with at least n digits can be entered. |
^ \ D {m, n} $ |
Only m ~ can be input ~ N-digit number |
^ (0 | [1-9] [0-9] *) $ |
Only numbers starting with zero or zero |
^ [0-9] + (. [0-9] {2 })? $ |
Only positive numbers with two decimal places can be entered. |
^ [0-9] + (. [0-9] {1, 3 })? $ |
Only 1 ~ Positive number of three decimal places |
^ \ +? [1-9] [0-9] * $ |
Only a non-zero positive integer can be entered. |
^ \-[1-9] [] 0-9 "* $ |
Only a non-zero negative integer can be entered. |
^. {3} $ |
Only 3 characters can be entered |
^ [A-Za-z] + $ |
You can only enter a string consisting of 26 English letters. |
^ [A-Za-z0-9] + $ |
Only strings consisting of digits and 26 English letters can be entered. |
^ \ W + $ |
Only strings consisting of digits, 26 English letters, or underscores can be entered. |
^ [A-zA-Z] \ w {5, 17} $ |
Verify User Password: starts with a letter and ranges from 6 ~ It can only contain characters, numbers, and underscores. |
[^ % & ',; =? $ \ X22] + |
Check whether ^ % & ',; =? $ \ "And other characters |
^ [\ U4e00-\ u9fa5] {0,} $ |
Only Chinese characters can be entered |
^ \ W + ([-+.] \ w +) * @ \ w + ([-.] \ w + )*\. \ w + ([-.] \ w +) * $ |
Verify Email address |
^Http ://([\ W-] + \.) + [\ w-] + (/[\ w -./? % & =] *)? $ |
Verify InternetURL |
^ \ D {15} | \ d {18} $ |
ID number for verification (15-digit or 18-digit) |
^ (2 [0-4] \ d | 25 [0-5] | [01]? \ D ?) \.) {3} (2 [0-4] \ d | 25 [0-5] | [01]? \ D ?) $ |
Verify IP Address |
(\ W) \ 1 |
Match two overlapping characters For example, "aabbc11asd", the returned results are aa bb 11, three groups of match |
<(? <Tag> [^ \ s>] +) [^>] *>. * </\ k <tag> |
Matched HTML tags |
(?!) |
No, negative declaration The following example shows how to obtain all the content in a <a> tag pair, even if it contains other HTML tags. string newsContent = @"url:<a href=""1.html"">test<span style=""color:red;""> Regex</span></a>."; Regex regEnd = new Regex(@"<\s*a[^>]*>([^<]|<(?!/a))*<\s*/a\s*>",RegexOptions.Multiline); |