Zzc # Regular Expression Summary

C # Regular Expression Summary

Address: http://www.cnblogs.com/maxianghui/archive/2006/05...

Really good. Thanks to this friend.

Only numbers are allowed: "^ [0-9] * $ ".
You can only enter n digits: "^" d {n} $ ".
You can only enter at least N digits: "^" d {n,} $ ".
Only M ~ can be input ~ N-digit :. "^" D {m, n} $"
Only numbers starting with zero and non-zero can be entered: "^ (0 | [1-9] [0-9] *) $ ".
Only positive numbers with two decimal places can be entered: "^ [0-9] + (. [0-9] {2 })? $ ".
Only 1 ~ Positive number of three decimal places: "^ [0-9] + (. [0-9] {1, 3 })? $ ".
Only a non-zero positive integer can be entered: "^" +? [1-9] [0-9] * $ ".
You can only enter a non-zero negative integer: "^"-[1-9] [] 0-9 "* $.
Only 3 characters can be entered: "^. {3} $ ".
You can only enter a string consisting of 26 English letters: "^ [A-Za-Z] + $ ".
You can only enter a string consisting of 26 uppercase letters: "^ [A-Z] + $ ".
You can only enter a string consisting of 26 lower-case English letters: "^ [A-Z] + $ ".
You can only enter a string consisting of a number and 26 English letters: "^ [A-Za-z0-9] + $ ".
You can only enter a string consisting of digits, 26 English letters, or underscores: "^" W + $ ".
Verify the User Password: "^ [A-Za-Z]" W {5, 17} $ ". The correct format is: start with a letter, with a length of 6 ~ It can only contain characters, numbers, and underscores.
Check whether ^ % & ',; =? $ "" And other characters: "[^ % & ',; =? $ "X22] + ".
Only Chinese characters can be entered: "^ [" u4e00-"u9fa5] {0,} $"
Verify email address: "^" W + ([-+.] "W +) * @" W + ([-.] "W + )*". "W + ([-.] "W +) * $ ".
Verify interneturl: "^ http: // ([" w-] + ".) + [" w-] + (/["w -./? % & =] *)? $ ".
Verification phone number: "^ (" ("d {3, 4}-) |" d {3.4 }-)? "D {7,8} $" correct format: "XXX-XXXXXXX", "XXXX-XXXXXXXX", "XXX-XXXXXXX", "XXX-XXXXXXXX", "xxxxxxx" and "XXXXXXXX ".
Verify the ID card number (15 or 18 digits): "^" d {15} | "d {18} $ ".
12 months of verification: "^ (0? [1-9] | 1 [0-2]) $ "the correct format is:" 01 "~ "09" and "1 "~ "12 ".
31 days of verification for a month: "^ (0? [1-9]) | (1 | 2) [0-9]) | 30 | 31) $ "the correct format is;" 01 "~ "09" and "1 "~ "31 ".
Use regular expressions to restrict text box input in a webpage form:

Use
The regular expression can only contain Chinese characters: onkeyup = "value = value. Replace (/[^" u4e00-"u9fa5]/g ,'')"
Onbeforepaste = "clipboardData. setdata ('text', clipboardData. getdata ('text'). Replace (/[^" u4e00-"u9fa5]/g ,''))"

Only full-width characters can be entered using regular expressions: onkeyup = "value = value. Replace (/[^" uff00-"Uffff]
/G ,'')"
Onbeforepaste = "clipboardData. setdata ('text', clipboardData. getdata ('text'). Replace (/[^" uff00-"Uffff]/g ,''))"

Use a regular expression to limit that only numbers can be entered: onkeyup = "value = value. Replace (/[^" d]/g ,'')
"Onbeforepaste =" clipboardData. setdata ('text', clipboardData. getdata ('text'). Replace (/[^ "d]/g ,''))"

Only numbers and English characters can be entered with a regular expression: onkeyup = "value = value. Replace (/[" W]/g ,'')
"Onbeforepaste =" clipboardData. setdata ('text', clipboardData. getdata ('text'). Replace (/[^ "d]/g ,''))"

Javascript programs that extract file names from URLs using regular expressions. the following result is page1.

S = "http://www.9499.net/page1.htm"
S = S. Replace (/(. * "/) {0,} ([^".] +). */ig, "$2 ")
Alert (s)

Match double-byte characters (including Chinese characters): [^ "x00-" xFF]

Application: Calculate the length of a string (two-byte length Meter 2, ASCII character meter 1)

String. Prototype. Len = function () {return this. Replace ([^ "x00-" xFF]/g, "AA"). length ;}

Regular Expression matching empty rows: "N [" s |] * "R

Regular Expressions matching HTML tags:/<(. *)>. * <"/" 1 >|< (. *) "/>/

Regular Expression matching spaces at the beginning and end: (^ "s *) | (" s * $)

String. Prototype. Trim = function ()
{
Return this. Replace (/(^ "s *) | (" s * $)/g ,"");
}

Use regular expressions to break down and convert IP addresses:

The following is a javascript program that uses regular expressions to match IP addresses and convert IP addresses to corresponding values:

Function ip2v (IP)
{
Re =/("d +)". ("d +)/g // The regular expression that matches the IP address
If (Re. Test (IP ))
{
Return Regexp. $1 * Math. Pow (255) + Regexp. $2 * Math. Pow () + Regexp. $3 * + Regexp. $4*1
}
Else
{
Throw new error ("not a valid IP address! ")
}
}

However, if the above program does not use regular expressions, it may be easier to directly use the split function to separate them. The program is as follows:

VaR IP = "10.100.0000168"
IP = IP. Split (".")
Alert ("the IP value is: "+ (IP [0] * 255*255*255 + IP [1] * 255*255 + IP [2] * 255 + IP [3] * 1 ))
Symbol explanation:

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 location 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}
N is a non-negative integer. Match n times. For example, 'O {2} 'cannot match 'O' in "Bob", but can match two o in "food.

{N ,}
N is a non-negative integer. Match at least N times. 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}
Both m and n are non-negative integers, where n <= m. Match at least N times and at most m times. 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 })
Later, the matching mode is non-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
"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)
Match pattern and obtain this match. The obtained match can be obtained from the generated matches set. The submatches set is used in VBScript, and $0… is used in JScript... $9 attribute. To match the parentheses, use '"(' or '")'.

(? : Pattern)
Horse
Match results are not obtained, that is, this is a non-get match and is not stored for future use. This is using the "or" character (|)
It is useful to combine all parts of a pattern. For example, 'industr (? : Y | ies'
A simpler expression.

(? = Pattern)
Forward pre-query, in any match Pattern
To 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 3.1"
In
"Windows ". 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
Forward query, where no pattern matches
To 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 2000"
In
"Windows ". 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
Match X or Y. 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
Match A Word boundary, that 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
Match the control characters specified by X. For example, "cm" matches a control-M or carriage return character. The value of X must be either a A-Z or 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
Match n, where N is the 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 use ASCII encoding ..

"Num
Matches num, where num is 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 there are at least N obtained subexpressions before "N", n is a backward reference. Otherwise, if n is an octal digit (0-7), n is an octal escape value.

"Nm
Mark
Identifies an octal escape value or a backward reference. If there are at least nm subexpressions before "Nm", the NM is a backward reference. If there is at least N before "Nm ",
N is a backward reference followed by text M. If none of the preceding conditions are met, if n and m are octal digits (0-7), then "nm
Match the octal escape value nm.

"NML
If n is an octal number (0-3) and M and l are Octal numbers (0-7), the octal escape value NML is matched.

"UN
Match n, where n is a Unicode character represented by four hexadecimal numbers. For example, "u00a9 matches the copyright symbol (?).