Regular expressions match both Chinese and English and regular expressions-regular expressions

Match Chinese: [\u4e00-\u9fa5]

English letter: [A-za-z]

Number: [0-9]

Match Chinese, English letters and numbers and _:

^[\u4e00-\u9fa5_a-za-z0-9]+$

At the same time determine the input length:

[\u4e00-\u9fa5_a-za-z0-9_] {4,10}

^[\w\u4e00-\u9fa5\uf900-\ufa2d]*$

1, a regular expression, contains only Chinese characters, numbers, letters, underscores can not be the beginning and end of the underscore:

^(?! _)(?!. *?_$) [a-za-z0-9_\u4e00-\u9fa5]+$ of which:

^ matches where the string begins

(?! _) cannot start with _

(?!. *?_$) cannot end with _

[a-za-z0-9_\u4e00-\u9fa5]+ at least one Chinese character, number, letter, underline

$ matches where the string ends

Put @ in front of the program, or you need to escape @ ^ (?! _)(?!. *?_$) [a-za-z0-9_\u4e00-\u9fa5]+$]

(or: @ "^" ^ (?!) _) \w* (? <!_) $ "or @" ^[\u4e00-\u9fa50-9a-za-z_]+$ ")

2, only contain Chinese characters, numbers, letters, underline, the underline position is not limited:

^[a-za-z0-9_\u4e00-\u9fa5]+$

3. A string of numbers, 26 English letters, or underscores

^\w+$

4.2~4 a Chinese character

@ "^[\u4e00-\u9fa5]{2,4}$";

5,

^[\w-]+ (\.[ \w-]+) *@[\w-]+ (\.[ \w-]+) +$

Used: (ABC) + to analyze: XYZAbcAbcAbcXYZAbcAb

XYZAbcAbcAbcXYZAbcAb6,
[^\u4e00-\u9fa50-9a-za-z_]
34555#5 '-->34555#5 '
[\u4e00-\u9fa50-9a-za-z_] eiieng_89_---> eiieng_89_
_ '; Eiieng_88&*9_--> _ '; ' Eiieng_88&*9_
_ '; ' Eiieng_88_&*9_--> _ '; ' eiieng_88_&*9_ Public
bool Regexname (string str)
{
bool Flag=regex.ismatch (str,@ "^[a-za-z0-9_\ u4e00-\u9fa5]+$ ");
return flag;
}
Regex reg=new Regex ("^[a-za-z_0-9]+$"); 
if (Reg. IsMatch (s)) 
{ 
\ comply with rule 
} 
else 
{ 
\ exists an illegal character 
}

No longer than 7 characters, or 14 bytes (digits, letters and underscores) regular expressions
^[\u4e00-\u9fa5]{1,7}$|^[\da-za-z_]{1,14}$

Common regular expression of the encyclopedia! (For example: matching Chinese, matching HTML)

Matching regular expressions for Chinese characters: [U4E00-U9FA5]

Commentary: Matching Chinese is really a headache, with this expression will be easy to do

Match Double-byte characters (including Chinese characters): [^x00-xff]

Commentary: can be used to compute the length of a string (a double-byte character length meter 2,ascii 1 characters)

A regular expression that matches a blank row: ns*r

Commentary: can be used to delete blank lines

Regular expression:< matching HTML tags (s*?) [^>]*>.*?| <.*? />

Commentary: The online version is too bad, the above can only match the part of the complex nested tags still powerless

A regular expression that matches the end-end whitespace character: ^s*|s*$

Commentary: A useful expression that can be used to delete white-space characters (including spaces, tabs, page breaks, and so on) at the end of a line at the beginning

Regular expression matching an email address: w+ ([-+.] w+) *@w+ ([-.] w+) *.w+ ([-.] w+) *

Commentary: Form validation is useful

Regular expressions that match URL URLs: [a-za-z]+://[^s]*

Commentary: Online circulation of the version of the function is very limited, which can meet the basic requirements

Match account number is legal (beginning of letter, allow 5-16 bytes, allow alphanumeric underline): ^[a-za-z][a-za-z0-9_]{4,15}$

Commentary: Form validation is useful

Match domestic phone number: D{3}-d{8}|d{4}-d{7}

Commentary: Match form such as 0511-4405222 or 021-87888822

Matching Tencent QQ Number: [1-9][0-9]{4,}

Commentary: Tencent QQ number starting from 10000

Match China ZIP Code: [1-9]d{5} (?! D

Commentary: China postal code is 6 digits

Matching ID: d{15}|d{18}

Commentary: China's ID card is 15-or 18-digit

Matching IP address: d+.d+.d+.d+

Commentary: Useful when extracting IP addresses

Match a specific number:

^[1-9]d*$//Matching positive integer
^-[1-9]d*$//matching negative integers
^-? [1-9]d*$//matching integer
^[1-9]d*|0$//matching nonnegative integer (positive integer + 0)
^-[1-9]d*|0$//matching non positive integer (negative integer + 0)
^[1-9]d*.d*|0.d*[1-9]d*$//matching positive floating-point numbers
^-([1-9]d*.d*|0.d*[1-9]d*) $//matching negative floating-point number
^-? ([1-9]d*.d*|0.d*[1-9]d*|0?. 0+|0) $//matching floating-point number
^[1-9]d*.d*|0.d*[1-9]d*|0? 0+|0$//matching nonnegative floating-point number (positive floating-point number + 0)
^ (-([1-9]d*.d*|0.d*[1-9]d*)) |? 0+|0$//matching non-positive floating-point numbers (negative floating-point number + 0)

Commentary: useful when dealing with large amounts of data, pay attention to corrections when applied

Match a specific string:

^[a-za-z]+$//Match a string of 26 English letters
^[a-z]+$//Match a string of 26 uppercase letters
^[a-z]+$//Match string consisting of 26 lowercase letters
^[a-za-z0-9]+$//Match a string of numbers and 26 English letters
^w+$//Match A string of numbers, 26 English letters, or underscores

The validation features and their validation expressions when using the RegularExpressionValidator validation control are described below:

Only numbers can be entered: "^[0-9]*$"

Only n digits can be entered: "^d{n}$"

You can enter at least n digits: "^d{n,}$"

Only m-n digits can be entered: "^d{m,n}$"

Only numbers beginning with 0 and not 0 can be entered: ^ (0|[ 1-9][0-9]*) $ "

You can only enter positive real numbers with two decimal digits: ^[0-9]+ (. [ 0-9]{2})? $ "

You can only enter positive real numbers with 1-3 decimal digits: ^[0-9]+ (. [ 0-9]{1,3})? $ "

You can only enter a Non-zero positive integer: "^+?" [1-9] [0-9]*$]

You can only enter a Non-zero negative integer: "^-[1-9][0-9]*$"

You can only enter characters with a length of 3: "^. {3}$ "

You can only enter a string of 26 English letters: "^[a-za-z]+$"

You can only enter a string of 26 uppercase English letters: "^[a-z]+$"

You can only enter a string consisting of 26 lowercase English letters: "^[a-z]+$"

You can only enter a string of numbers and 26 English letters: "^[a-za-z0-9]+$"

You can only enter a string of numbers, 26 English letters, or underscores: "^w+$"

Verify user password: "^[a-za-z]w{5,17}$" in the correct format: Beginning with the letter, length between 6-18,

Only characters, numbers, and underscores can be included.

Verify that there are ^%& ',; =?$ ' characters: "[^%&",; = $x 22]+ "

Only Chinese characters can be entered: "^[u4e00-u9fa5],{0,}$"

Verify email Address: "^w+[-+." w+) *@w+ ([-.] w+) *.w+ ([-.] w+) *$ "

Verify InternetURL: "^http://([w-]+.) +[w-]+ (/[w-./?%&=]*)? $ "

Verify phone Number: "^ ((d{3,4}) |d{3,4}-)? d{7,8}$"

The correct format is: "Xxxx-xxxxxxx", "xxxx-xxxxxxxx", "xxx-xxxxxxx",

"Xxx-xxxxxxxx", "XXXXXXX", "XXXXXXXX".

Verify ID Number (15-bit or 18-digit): "^d{15}|d{}18$"

Verify 12 months of the year: "^" (0?[ 1-9]|1[0-2]) $ "The correct format is:" 01 "-" 09 "and" 1 "" 12 "

Verify one months of 31 days: "^ (0?[ 1-9]) | ((1|2) [0-9]) |30|31) $ "

The correct format is: "01" "09" and "1" "31".

Matching regular expressions for Chinese characters: [U4E00-U9FA5]

Match Double-byte characters (including Chinese characters): [^x00-xff]

A regular expression that matches a blank row: n[s|] *r

Regular expression matching HTML tags:/< (. *) >.*|< (. *)/>/

Matching a regular expression with a trailing space: (^s*) | (s*$)

Regular expression matching an email address: w+ ([-+.] w+) *@w+ ([-.] w+) *.w+ ([-.] w+) *

A regular expression that matches URL URLs: http://([w-]+.) +[w-]+ (/[w-/?%&=]*)?

(1) Application: Computes the length of the string (a double-byte character length meter 2,ascii character count 1)

String.prototype.len=function () {return This.replace ([^x00-xff]/g, "AA"). Length;}

(2) Application: JavaScript does not have a trim function like VBScript, we can use this expression to implement

String.prototype.trim = function () 
{return 
this.replace (^s*) | (　　s*$)/g, ""); 
(3) Application: Convert the IP address 
function ip2v (IP)//IP address to the corresponding value 
{ 
re=/(d+) using regular expression decomposition and conversion. d+). (d+). (d+)/g//matching IP address regular expression 
if (Re.test (IP)) 
{return 
Regexp.$1*math.pow (255,3)) +regexp.$2*math.pow (255,2)　　+regexp.$3*255+regexp.$4*1 
} 
else 
{ 
throw new Error ("not a valid IP address!") 
} 

(4) Application: JavaScript program to extract filename from URL address

S= "http://www.9499.net/page1.htm";

S=s.replace (/. * *) {0,} ([^.] +). */ig, "$");//page1.htm

(5) Application: Using regular expressions to restrict the input of text boxes in Web Forms

Restrict the use of regular expressions to only Chinese: 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 with regular expression restrictions: onkeyup= "Value=value.replace" (/[^uff00-uffff]/g, ')

"Onbeforepaste=" clipboarddata.setdata (' text ', Clipboarddata.getdata (' text '). Replace (/[^uff00-uffff]/g, ')) "

Only numbers can be entered with regular expression restrictions: onkeyup= "Value=value.replace" (/[^d]/g, ') "onbeforepaste=" Clipboarddata.setdata

(' Text ', Clipboarddata.getdata (' text '). Replace (/[^d]/g, ') "

Only numbers and English can be entered with regular expression restrictions: onkeyup= "Value=value.replace" (/[w]/g, ') "onbeforepaste=" Clipboarddata.setdata

(' Text ', Clipboarddata.getdata (' text '). Replace (/[^d]/g, '

The above is a small series to introduce the regular expression matching both in English and common regular expressions, I hope to help you!