20140829 share the regular expression outline

1. Regular Expression

^ Starts with [^] Not

$ End (per line)

\ Escape

. Match other words except \ n

? Previous 0 or 1 time

* The previous 0 + times

{N} n times

{N,} n + times

{N, m} n-m times

| Or

[123] [123] Set, [123] matching is not valid

[1-3] [A-Z] [A-Z] Set Range

[^ 123] [^ A-Z] The set is not

\ D 0-9

\ D non-numeric

\ N \ r

\ S is empty, including \ f \ n \ r \ t \ v

\ S is not empty

() Group

2. Regular Expression Composition

/Regular/Modifier

New Regexp ('reg', 'modifier ');

Modifier:

I is case insensitive

G Global

M multiple rows (if enabled, ^ $ indicates the target of each behavior)

3. Combination

^ 1 [3-8] \ D {9} $

^ \ D {7} $7 digits

^ (\ D {4 })? \ D {7} $ Add a four-digit area code

^ (\ D {4 }\-?)? \ D {7} $ Add a four-digit area code-

^ (0 \ D {3 }\-?)? \ D {7} $ must start with 0

^ (0 \ D {3 }\-?)? \ D {7} | (0 \ D {2 }\-?)? \ D {8}) $3-digit area code

^ (\ 0 \ D {3 }\-)? [1-9]) | (0 \ D {2 }\-)? [1-9] \ D) \ D {6} $3 4 // incorrect, Example

4. Greedy

1 (.*)? 0 => 10,110,100.

1 (.*?) 0 => 132323230, 1 ultra-large scale fsdfsdf0

Comment out:

<! \-([\ S] *?) \->

\/\/(.*?) $

Tag removal:

<\/? ([A-Za-Z] +?)>

5. assertion/pre-check/non-capture

? : Non-capturing

? = Forward judgment

?! Positive/false Determination

? <= Reverse determination (not supported by JS)

? <! Reverse no determination (not supported by JS)

1. Non-capturing

(? : \ D) [A-Za-Z] + // The group of numbers will not be captured later. It is usually used for match and exec. Non-capture can improve performance to some extent.

2, must be letters + numbers

^ (?! \ D + $ )(?! [A-Za-Z] + $) [0-9a-za-z] {1,} $

=> Convert

^

(?! \ D + $) // not end with a full number

(?! [A-Za-Z] + $) // not end with a full letter

[0-9a-za-z] {1,} // number + more than 1 letter

$

3. It must contain @ letters or numbers.

^ (? =. * @. *) [[Email protected] {2,} $

4. It must contain @, but cannot start or end

^ (? = .*@.*)(?! ^ @(.*))(?! (. *) @ $) [[Email protected] {2,} $

=>

^

(? =. * @. *) // Must contain @
(?! ^ @ (. *) // Cannot start @
(?! (. *) @ $) // It cannot end @
[[Email protected] {2,} // two or more letters or numbers @

$

6. Regular Expression

Test to verify whether the matching is successful

Exec is similar to string. match, but it is said there is a difference

/REG/. Test (value)

/REG/ig.exe C (value)

String. Match (/REG/g)

String. Split (/REG /)

7. Application scenarios

1. Path for collecting images: (the idea of js php is the same)

VaR STR = 'capture all the source code of the page to fffdsfsd fsdfsd fsdf ';
VaR arr = Str. Match (/] +?> /G) | []; // capture all image tags first
Arr. foreach (function (VAL) {// traverses all the results. Here Val gets the tag STR for each image.
VaR STR = Val. Match (/src = ['"]? (. + ?) ['"]? /) | ['',''];
Alert (STR [1]);

});

2. Password Complexity

VaR pass = 'fsdfsdf ';
VaR arr = pass. Match (/^ (? :( \ D +) | ([A-Z] +) | ([A-Z] +) | ([A-Za-Z] +) | ([a-zA-Z0-9] + )) $ /);
Arr [0] // Summary Result
Arr [1] // pure number
Arr [2] // lowercase letters only
Arr [3] // uppercase letters only

20140829 share the regular expression outline