Example Analysis of js regular expression Verification

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The following functions are called:

Function check () {var bb = document.getElementById ("txt_id"). Value;//txt_id is the ID alert (ismobile (bb)) of the text box; / / ismobile represents any of the following function names}

HTML Code:

= 48&&keycode & /'|

Regular expression [^ & / |'\] +

Date verification

Matching forms such as: 20030718pr 030718

Scope: 1900 Murray 2099

Regular expression (19) {1} | (20) {1}) d {2}) | d {2}) [01] {1} d {1} [0-3] {1} d {1}

Regular expressions that match Chinese characters: [\ u4e00 -\ u9fa5]

Note: matching Chinese is really a headache. It's easy to have this expression.

Match double-byte characters (including Chinese characters): [^\ X00 -\ xff]

Note: can be used to calculate the length of a string (a double-byte character length meter 2 ~ ~ ASCII character counter 1)

A regular expression that matches a blank line:\ n\ s*\ r

Comment: can be used to delete blank lines

A regular expression that matches the HTML tag:

< (\S*?)[^>

] * >. *? |

< .*? />

Commentary: the version circulated on the Internet is too bad, the above one can only match part of it, and there is still nothing I can do about complex nested tags.

Regular expression that matches the leading and trailing white space characters: ^\ s* |\ sblank $

Comment: a very useful expression that can be used to delete white space characters (including spaces, tabs, page feeds, etc.) at the beginning and end of a line

The regular expression that matches the Email address:\ W + ([- +.]\ w +) * @\ w + ([-.]\ w +) *.\ w + ([-.]\ w +) *

Comment: form validation is very useful

Regular expression that matches the URL URL: [a-zA-z] +: / / [^\ s] *

Note: the function of the version circulated on the Internet is very limited, and the above version can basically meet the needs.

Whether the matching account is legal (5-16 bytes are allowed at the beginning of the letter, and alphanumeric underscores are allowed): ^ [a-zA-Z] [a-zA-Z0-9 _] {4j 15} $

Comment: form validation is very useful

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

Commentary: matching forms such as 0511-4405222 or 021-87888822

Match Tencent QQ number: [1-9] [0-9] {4,}

Commentary: Tencent QQ starts from 10000

Match the postcode of China: [1-9]\ d {5} (?!\ d)

Commentary: the postal code of China is 6 digits

Match ID:\ d {15} |\ d {18}

Commentary: Chinese ID cards are 15 or 18 digits

Match ip address:\ d +\.\ d +\.\ d +

Note: useful when extracting ip addresses

Extract the ip address from the information:

(\ d+)\. (\ d+)

Extract the Chinese mobile phone number from the information:

(86) * 013\ d {9}

The Chinese fixed telephone number extracted from the information:

(\ (\ d {3pr 4}\) |\ d {3pr 4}-|\ s)?\ d {8}

Chinese phone numbers (including mobile and landline phones) in the extracted information:

(\ (\ d {3pr 4}\) |\ d {3pr 4}-|\ s)?\ d {7pr 14}

The postcode of China in the extracted information:

[1-9] {1} (\ d +) {5}

The Chinese ID card number extracted from the information:

\ d {18} |\ d {15}

Extract integers from the information:

\ d +

Extract the floating point number (that is, decimal) in the information:

(-?\ d *)\. D +

Extract any number from the information:

(-?\ d *) (\.\ d +)?

Extract the Chinese string in the information:

[\ u4e00 -\ u9fa5] *

Extract a double-byte string (Chinese character) from the information:

[^\ X00 -\ xff] *

Extract the English string from the information:

\ w *

Extract web links from the information:

(h | H) (r | R) (e | E) (f | F) * = * ('| ")? (\ w |\.) + ('|" | * | >)?

The email address in the extracted information:

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

Extract the picture link in the information:

(s | S) (r | R) (c | C) * = * ('| ")? (\ w |\ |\ /) + ('|" | * | >)?

Match specific numbers:

^ [1-9]\ positive integer matching $/ /

^-[1-9]\ negative integer matching $/ /

^ -? [1-9]\ match integer

^ [1-9]\ d* | 0 $/ / matches a non-negative integer (positive integer + 0)

^-[1-9]\ d* | 0 $/ / matches non-positive integers (negative integers + 0)

^ [1-9]\ d *\.\ d * | 0\.\ d * [1-9]\ dfloat $/ / matches positive floating point numbers

^-([1-9]\ d *.\ d * | 0.\ d * [1-9]\ d *) $/ / matches negative floating point numbers

^ -? ([1-9]\ d *.\ d * | 0\.\ d * [1-9]\ d * | 0?\ .0 + | 0) $/ / match floating point number

^ [1-9]\ d *.\ d * | 0\.\ d * [1-9]\ d * | 0?\ .0 + | 0 $/ / matches non-negative floating point numbers (positive floating point number + 0)

^ (- ([1-9]\ d *\.\ d * | 0\.\ d * [1-9]\ d *)) | 0?\ .0 + | 0 $/ / matches non-positive floating point numbers (negative floating point + 0)

Commentary: useful when dealing with a large amount of data, pay attention to corrections in specific applications

Match a specific string:

^ [A-Za-z] + $/ / matches a string of 26 English letters

^ [Amurz] + $/ / matches a string of 26 English letters in uppercase

^ [amurz] + $/ / matches a string of 26 lowercase letters

^ [A-Za-z0-9] + $/ / matches a string of numbers and 26 letters

^\ w match $/ / match a string consisting of numbers, 26 letters, or underscores

Commentary: some of the most basic and most commonly used expressions

/ the first 4 lines are used to protect js code from being downloaded

/ / basic regular expression /

/ / non-empty verification

Function NotNull (str) {return (stringing = "");}

/ / email address verification

Function checkEmail (str) {

/ / regular expression of email address

IsEmail1=/ ^\ w + ([\.\ -]\ w +) *\ @\ w + ([\.\ -]\ w +) *.

/ / regular expression of email address

IsEmail2=/. * @ [^ _] * $/

/ / verify the email address and return the result

Return (isEmail1.test (str) & & isEmail2.test (str);}

/ / ID card verification

Function checkIDCard (str) {

/ / ID card regular expression (15 bits)

IsIDCard1=/ ^ [1-9]\ d {7} ((0\ d) | (1 [0-2])) (([0 | 1 | 2]\ d) | 3 [0-1])\ d {3} $/

/ / ID card regular expression (18 bits)

IsIDCard2=/ ^ [1-9]\ d {5} [1-9]\ d {3} ((0\ d) | (1 [0-2])) (([0 | 1 | 2]\ d) | 3 [0-1]))\ d {4} $/

/ / verify the ID card and return the result

Return (isIDCard1.test (str) | | isIDCard2.test (str);}

/ / IP verification

Function checkIP (str) {

/ / IP regular expression

IP=' (25 [0-5] | 2 [0-4]\\ d | 1\\ d\\ d |\\ d\ d |\\ d)'; IPdot=IP+'\\.; isIPaddress=new RegExp ('^'+ IPdot+IPdot+IPdot+IP+'$')

/ / verify IP and return the result

Return (isIPaddress.test (str));}

/ / Home page (URL) verification

Function checkHomepage (str) {

/ / Home page regular expression

/ / isHomepage=/ ^\ w + ([\.\ -]\ w) * $/; isHomepage=/ ^\ w + (\.\ w +) +\.

/ / verify the home page and return the result

Return (isHomepage.test (str));}

/ / whether it is a number or not

Function isNum (str) {/ / isNumber=/ ^ ([1-9]\ d * (\.\ d +)?) | (\ d + (\.\ d +)) $/; isNumber=/ ^\ d + (\.\ d +)? $/

/ / verify and return the result

Return (isNumber.test (str));}

/ / whether it is an integer

Function isInt (str) {isInteger=/ ^\ dcards /

/ / verify and return the result

Return (isInteger.test (str));}

/ / whether it is a letter or not

Function isChar (str) {isCharacter=/ ^ [A-Za-z] + $/

/ / verify and return the result

Return (isCharacter.test (str));}

/ basic popup window /

Function checkBoolean (bv,i,w) {if (bv==false) {try {i.focus ();} catch (e) {} alert (w); return false;} return true}

/ element and value judgment /

Selected

Function checkElement_selected (item,alert_str) {if (item.type== "select-one") return checkElement_NotNull (item,alert_str); if (alert_str.length==0) alert_str=item.title+ "is required!" ; rt=false; if (item.length > 0) {for