Regular introduction
js appears: Form Validation
Regular Expressions:
A character rules described
objects , can check whether a character string containing a character, the character matching substrings do replaced or removed from a condition in a string like.
Regular grammar based on an ancient language Perl
Regular use and create
1. Use:
Can not be used directly, with the method, it is generally used to verify the regular characters
Character: str.match (reg) str.replace (reg) str.search ()
Regular: reg.test (str)
2. Regular features:
Screened qualified string, replacing qualified string of characters verify compliance with rules
3. Create
1) a constructor argument:
var REG1 = new new the RegExp ( "a" ); var STR = "adassdfsd" ; the console.log (str.match (REG1)) // output matching a character
2) literal way:
var REG2 = / a / ; the console.log (str2.match (REG2)); // the output of a matching character
/ / Is a regular expression identifier
"" Is a string identifier
[] Is an array of identifiers
{} Is the identifier of the object
Regular verification:
var reg = / [0-9] /;
reg.test (str) // returns true if the verification is successful, false indicates failure
String .replace (oldstr, newstr) function and string .match (regular) function
1) Function of the replace function to replace one string :( only, and the case has not replaced)
Will replace the old string to the new string
2) match the string of functionality:
Extract all the things you want,
it returns an array containing all eligible characters
Regular content:
Modifiers:
Canonical regularization of modifiers, written on the back of expression / n:
G
: represents the global match finds all
i
: ignore case represents
var STR = "abYchdYewyzyhcyaq" the console.log (str.replace ( / Y / G, "Yu")) // abYchdYew z Yu Yu Yu hc AQ the console.log (str.replace (/ Y / GI, "Yu") ) // ab & chd Yu Yu ew z Yu Yu Yu aq hc
Quantifier: Qualifier
+ Represents at least one uncapped
() A separate part
[] A separate part, but the interior of the Meta content is character or relationship, a Ghost character, one character can match
^ Inside the symbol represents a non Ghost, except
| Or ? Zero or 1 * zero or more times
{n} to match at least n times {n, m} matches at least n times, matching up m times
Note: After the qualifier followed? , Matched by greed become non-greedy match
Escapes:
\
D - [0-9] Digital
\ W
- [A-z0-9_] numbers, letters, underline
\
S - blank characters (spaces)
\ D
- [^ 0-9] non-numeric
\ W is
- [^ A-z0-9_] non-numeric, alphabetic, underscore
\
S - non-whitespace characters
Representatives of all (not recommended)
var REG = / <. +> / G // filtration, angle brackets represents something not console.log (str.replace (reg. "" ))
Regular greed Law:
var REG = / <[^ <>] +> / G the console.log (str.replace (REG, "")) // represents the angle brackets do something really
Modify the partial authentication:
We need to give regular expression, coupled with the beginning and end, indicating the end of validation from the beginning of the string to string
^ Indicates the beginning
$ Represents the end
Commonly used detection method:
1. Chinese Detection
unicode encoded Chinese surveillance: / ^ [\ u2E80- \ u9FFF] + $ /
2. User name detection
Regular: / ^ [a-z0-9 _-] {3,16} $ /
3. mail detection
/^([a-z0-9_\.-]+)@([\da-z\.-]+)\.([a-z\.]{2,6})$/
Can appear multiple times (underlined alphanumeric .-) may occur multiple @ (.- alphanumeric). 2-6 or letters.
/^[a-z\d]+(\.[a-z\d]+)*@([\da-z](-[\da-z])?)+(\.{1,2}[a-z]+)+$/
There may be multiple (alphanumeric) may have a plurality of free (plurality (alphanumeric)) may be a plurality @ (alphanumeric there may be no 1 (- alphanumeric)) can have multiple (2 or 1 a plurality of letters)
4.URL detection
/^(https?:\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w\.-]*)*\/?$/
There are 1 or 0 times (http times with a 1 or 0 s: //) may be a plurality (alphanumeric .-) 2-6 (letters.) May be 0 or more (or a plurality may be 0. / .- alphanumeric underlined) may be 0 or 1 /
5.HTML label inspection
/^<([a-z]+)([^<]+)*(?:>(.*)<\/\1>|\s+\/>)$/
<Plurality (letters), or may be a plurality of 0 (all the characters except <a) />
<Plurality (letters), or may be a plurality of 0 (all the characters except <a)> any number of characters </ repetition of the first portion of the plurality of letters>
6. replace a character in all the special characters with a positive:
/ [ \w_ ]+ /g
Regular Expression Manual
: http://tool.oschina.net/uploads/apidocs/jquery/regexp.html